Pub Date : 2026-04-15Epub Date: 2026-01-08DOI: 10.1016/j.saa.2026.127462
Xingyue Li , Zi Wang , Jialin Bai , Botao Yao , Yixiao Dong , Yanni Zhao , Zhiqiang Wang , Ruiting Zhang , Lin Ma , Ke Lin
The aroma of liquor is one of the key indicators used to evaluate the liquor. Therefore, accurately determining the composition and its content of a liquor's aroma is crucial for assess its quality. In this study, Fourier transform infrared difference spectroscopy was used to record the aroma composition of Chinese liquor at room temperature. Through measuring the infrared absorption spectra of the volatiles from liquor and an aqueous ethanol solution, the spectra of the trace chemical compounds in the aroma were obtained using the difference spectroscopy. According to the infrared absorption spectra of standard compounds, the vibrational bands in the IR spectra of the aroma in eight different brands of Chinese liquor were regarded as the molecular vibration from ethyl acetate, ethyl lactate, ethyl caproate, caproic acid and isoamyl alcohol. Using the Lambert Beer's law, the contents of these trace compounds were quantitatively determined to be around 1–6 mg/L. This study demonstrates the difference IR spectroscopy is a powerful tool for assess quality of liquor.
{"title":"The composition and content of trace compounds in the aroma of Chinese liquor by Fourier transform infrared (FTIR) difference spectroscopy","authors":"Xingyue Li , Zi Wang , Jialin Bai , Botao Yao , Yixiao Dong , Yanni Zhao , Zhiqiang Wang , Ruiting Zhang , Lin Ma , Ke Lin","doi":"10.1016/j.saa.2026.127462","DOIUrl":"10.1016/j.saa.2026.127462","url":null,"abstract":"<div><div>The aroma of liquor is one of the key indicators used to evaluate the liquor. Therefore, accurately determining the composition and its content of a liquor's aroma is crucial for assess its quality. In this study, Fourier transform infrared difference spectroscopy was used to record the aroma composition of Chinese liquor at room temperature. Through measuring the infrared absorption spectra of the volatiles from liquor and an aqueous ethanol solution, the spectra of the trace chemical compounds in the aroma were obtained using the difference spectroscopy. According to the infrared absorption spectra of standard compounds, the vibrational bands in the IR spectra of the aroma in eight different brands of Chinese liquor were regarded as the molecular vibration from ethyl acetate, ethyl lactate, ethyl caproate, caproic acid and isoamyl alcohol. Using the Lambert Beer's law, the contents of these trace compounds were quantitatively determined to be around 1–6 mg/L. This study demonstrates the difference IR spectroscopy is a powerful tool for assess quality of liquor.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127462"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study developed an aptamer sensor based on surface-enhanced Raman scattering (SERS) for the highly sensitive and selective detection of acrylamide (AAm) in food. Au@4MBA@Ag core-shell nanoparticles were synthesized and functionalized with thiol-modified AAm aptamers (Apt) to serve as signal probes. Meanwhile, Fe₃O₄@PEI@Ag magnetic nanoparticles were prepared and modified with complementary DNA (cDNA) to act as capture probes. The two probes were combined through Apt-cDNA hybridization to form a complete SERS sensing system. The structure and surface properties of Fe₃O₄@PEI@Ag were systematically characterized using various characterization methods, and its SERS enhancement performance was validated using Rhodamine 6G (R6G). Similarly, Au@4MBA@Ag was characterized to confirm its excellent SERS activity and reproducibility. The constructed SERS aptamer sensor achieves a detection limit as low as 3.26 × 10−10 M for AAm, and the aptamer sensor shows no response to structural analogues (such as acrylic acid and methacrylamide), demonstrating excellent specificity. In actual sample testing, the recovery rate was 90%–110%, highly consistent with HPLC detection results (recovery rate of 90%–110%). Therefore, this sensor offers advantages such as ease of operation, rapid detection, and strong resistance to interference, providing a reliable new method for trace detection of AAm in food.
{"title":"A dual-probe SERS aptasensor for ultrasensitive detection of acrylamide in food","authors":"Xiaoying Yang, Qian Liu, Lisha Xiang, Xiang Li, Tianxiang Li, Chao Kang, Dongmei Chen, Wanliang Yang","doi":"10.1016/j.saa.2025.127322","DOIUrl":"10.1016/j.saa.2025.127322","url":null,"abstract":"<div><div>This study developed an aptamer sensor based on surface-enhanced Raman scattering (SERS) for the highly sensitive and selective detection of acrylamide (AAm) in food. Au@4MBA@Ag core-shell nanoparticles were synthesized and functionalized with thiol-modified AAm aptamers (Apt) to serve as signal probes. Meanwhile, Fe₃O₄@PEI@Ag magnetic nanoparticles were prepared and modified with complementary DNA (cDNA) to act as capture probes. The two probes were combined through Apt-cDNA hybridization to form a complete SERS sensing system. The structure and surface properties of Fe₃O₄@PEI@Ag were systematically characterized using various characterization methods, and its SERS enhancement performance was validated using Rhodamine 6G (R6G). Similarly, Au@4MBA@Ag was characterized to confirm its excellent SERS activity and reproducibility. The constructed SERS aptamer sensor achieves a detection limit as low as 3.26 × 10<sup>−10</sup> M for AAm, and the aptamer sensor shows no response to structural analogues (such as acrylic acid and methacrylamide), demonstrating excellent specificity. In actual sample testing, the recovery rate was 90%–110%, highly consistent with HPLC detection results (recovery rate of 90%–110%). Therefore, this sensor offers advantages such as ease of operation, rapid detection, and strong resistance to interference, providing a reliable new method for trace detection of AAm in food.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127322"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-13DOI: 10.1016/j.saa.2026.127473
Jun Dong , Yimeng Fan , Ziqing Fang , Guanwei Feng , Qingyan Han , Chengyun Zhang , Rong Chen , Jinchao Miao , Jianxia Qi , Wei Gao
Surface-enhanced Raman scattering (SERS) has emerged as a powerful tool for food safety analysis. We present a three-dimensional particle-in-cavity substrate that utilizes plasmonic cavity resonances for highly sensitive detection. Fabricated by a convenient transfer of AuNPs onto an anodic aluminum oxide (AAO) template, this design facilitates scalable production. The synergistic cavity-particle interplay yields a 4.24-fold SERS enhancement over a conventional flat Si substrate. The substrate demonstrated high sensitivity with a Rh6G enhancement factor of 1.77 × 109, excellent uniformity showcasing relative standard deviations of 9.17% for Rh6G and 8.54% for crystal violet, and strong log-concentration linearity with correlation coefficients reaching 0.988 for Rh6G and 0.989 for Crystal Violet. It maintained 60% of its initial signal intensity after 30 days of storage and achieved an aspartame detection limit as low as 0.0078 g/L, demonstrating its excellent detection capability.
{"title":"Fabrication of AAO-based 3D particle-in-cavity nanostructures for ultrasensitive SERS detection","authors":"Jun Dong , Yimeng Fan , Ziqing Fang , Guanwei Feng , Qingyan Han , Chengyun Zhang , Rong Chen , Jinchao Miao , Jianxia Qi , Wei Gao","doi":"10.1016/j.saa.2026.127473","DOIUrl":"10.1016/j.saa.2026.127473","url":null,"abstract":"<div><div>Surface-enhanced Raman scattering (SERS) has emerged as a powerful tool for food safety analysis. We present a three-dimensional particle-in-cavity substrate that utilizes plasmonic cavity resonances for highly sensitive detection. Fabricated by a convenient transfer of AuNPs onto an anodic aluminum oxide (AAO) template, this design facilitates scalable production. The synergistic cavity-particle interplay yields a 4.24-fold SERS enhancement over a conventional flat Si substrate. The substrate demonstrated high sensitivity with a Rh6G enhancement factor of 1.77 × 10<sup>9</sup>, excellent uniformity showcasing relative standard deviations of 9.17% for Rh6G and 8.54% for crystal violet, and strong log-concentration linearity with correlation coefficients reaching 0.988 for Rh6G and 0.989 for Crystal Violet. It maintained 60% of its initial signal intensity after 30 days of storage and achieved an aspartame detection limit as low as 0.0078 g/L, demonstrating its excellent detection capability.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127473"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146013940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-06DOI: 10.1016/j.saa.2025.127412
Indranath Mukhopadhyay
In this work, systematic and comprehensive studies of the energy states of triply deuterated methanol (CD3OH) in its ground vibrational state have been carried out using spectral studies in the far-infrared (FIR), sub-millimeter-wave (SMMW), and microwave (MW) regions. In the FIR region, a Synchrotron radiation-based Fourier transform spectrometer at the Canadian Light Sources (CLS) has been used to obtain a high-resolution (∼0.0017 cm−1) spectrum over 50–8000 cm−1 with a high signal-to-noise ratio (S/N) under various physical conditions. In the SMMW region, a backward wave-based very fast spectrometer was developed at the Ohio State University by F.C. DeLucia and coworkers. More than 3000 transition wavenumbers in the range of 117–960 GHz have been measured with an estimated uncertainty of 50–100 kHz. In the microwave region, approximately 2000 rotational transition frequencies have been measured in various laboratories over several decades, but have remained unpublished. In the ground torsional state, two K states (viz., K = 0 and 2) are so close to each other that they strongly interact through a ΔK = 2 interaction. In the first excited torsional state, the K = 7 and 9 A states also interact, mixing the states vigorously.
Due to the above interactions, a large number of forbidden transitions have been observed, which borrow intensity from the mixed states. The assignments have been thoroughly confirmed using combination loops. The observed transition frequencies have been fitted directly with the term values, which can reproduce the frequencies well within the experimental uncertainty of ±0.0002 cm−1. The Hamiltonian constants have also been obtained by fitting the transition frequencies. However, due to perturbations in the energy levels, they reproduced the transitions up to the second excited torsional state with reasonable accuracy of ∼0.01–0.05 cm-1, and with ∼0.1–0.5 cm-1 for higher-lying states. The pure torsional energies for the first five torsional states have been determined and plotted as a function of the axial component (K) of the rotational angular momentum. A detailed discussion has been included later in this report. Transition frequencies essential to represent the discussions have been included in the text, and more than 12,000 accurately measured transition wave numbers are included in Appendix I. The present work has also been used to calculate the frequencies of many FIR laser lines optically pumped by CO2 laser, with an accuracy an order of magnitude better than previously known.
{"title":"A comprehensive high-resolution spectral study of the ground vibrational state of triply deuterated methanol (CD3OH) using synchrotron radiation and backward wave oscillator-based spectrometer: Torsional energies and forbidden transitions","authors":"Indranath Mukhopadhyay","doi":"10.1016/j.saa.2025.127412","DOIUrl":"10.1016/j.saa.2025.127412","url":null,"abstract":"<div><div>In this work, systematic and comprehensive studies of the energy states of triply deuterated methanol (CD<sub>3</sub>OH) in its ground vibrational state have been carried out using spectral studies in the far-infrared (FIR), sub-millimeter-wave (SMMW), and microwave (MW) regions. In the FIR region, a Synchrotron radiation-based Fourier transform spectrometer at the Canadian Light Sources (CLS) has been used to obtain a high-resolution (∼0.0017 cm<sup>−1</sup>) spectrum over 50–8000 cm<sup>−1</sup> with a high signal-to-noise ratio (S/N) under various physical conditions. In the SMMW region, a backward wave-based very fast spectrometer was developed at the Ohio State University by F.C. DeLucia and coworkers. More than 3000 transition wavenumbers in the range of 117–960 GHz have been measured with an estimated uncertainty of 50–100 kHz. In the microwave region, approximately 2000 rotational transition frequencies have been measured in various laboratories over several decades, but have remained unpublished. In the ground torsional state, two K states (viz., K = 0 and 2) are so close to each other that they strongly interact through a ΔK = 2 interaction. In the first excited torsional state, the K = 7 and 9 A states also interact, mixing the states vigorously.</div><div>Due to the above interactions, a large number of forbidden transitions have been observed, which borrow intensity from the mixed states. The assignments have been thoroughly confirmed using combination loops. The observed transition frequencies have been fitted directly with the term values, which can reproduce the frequencies well within the experimental uncertainty of ±0.0002 cm<sup>−1</sup>. The Hamiltonian constants have also been obtained by fitting the transition frequencies. However, due to perturbations in the energy levels, they reproduced the transitions up to the second excited torsional state with reasonable accuracy of ∼0.01–0.05 cm-1, and with ∼0.1–0.5 cm-1 for higher-lying states. The pure torsional energies for the first five torsional states have been determined and plotted as a function of the axial component (K) of the rotational angular momentum. A detailed discussion has been included later in this report. Transition frequencies essential to represent the discussions have been included in the text, and more than 12,000 accurately measured transition wave numbers are included in Appendix I. The present work has also been used to calculate the frequencies of many FIR laser lines optically pumped by CO<sub>2</sub> laser, with an accuracy an order of magnitude better than previously known.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127412"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-17DOI: 10.1016/j.saa.2026.127479
Shuqi Tang, Hongda Wu, Yifeng Han
Hydrazine (N2H4) is a toxic industrial compound requiring sensitive and selective detection. We report a series of ratiometric fluorescent probes (RC-Ac, RC-Pr, RC-n-Bu, RC-i-Bu) based on a FRET system integrating coumarin and rhodol fluorophores. Among them, RC-n-Bu exhibited optimal performance, with minimal background hydrolysis and a high second-order rate constant (k2 = 49.4 M−1·min−1). RC-n-Bu showed a distinct ratiometric fluorescence shift upon hydrazine exposure, enabling precise quantification and excellent selectivity. It was successfully applied to live-cell and zebrafish imaging, and a portable test strip format allowed visual detection under UV light with smartphone-assisted analysis. This work offers a versatile platform for hydrazine monitoring in biological and environmental settings.
{"title":"A FRET-based ratiometric fluorescent probe for selective hydrazine detection, live imaging, and portable sensing","authors":"Shuqi Tang, Hongda Wu, Yifeng Han","doi":"10.1016/j.saa.2026.127479","DOIUrl":"10.1016/j.saa.2026.127479","url":null,"abstract":"<div><div>Hydrazine (N<sub>2</sub>H<sub>4</sub>) is a toxic industrial compound requiring sensitive and selective detection. We report a series of ratiometric fluorescent probes (<strong>RC-Ac</strong>, <strong>RC-Pr</strong>, <strong>RC-<em>n</em>-Bu</strong>, <strong>RC-<em>i</em>-Bu</strong>) based on a FRET system integrating coumarin and rhodol fluorophores. Among them, <strong>RC-<em>n</em>-Bu</strong> exhibited optimal performance, with minimal background hydrolysis and a high second-order rate constant (k<sub>2</sub> = 49.4 M<sup>−1</sup>·min<sup>−1</sup>). <strong>RC-<em>n</em>-Bu</strong> showed a distinct ratiometric fluorescence shift upon hydrazine exposure, enabling precise quantification and excellent selectivity. It was successfully applied to live-cell and zebrafish imaging, and a portable test strip format allowed visual detection under UV light with smartphone-assisted analysis. This work offers a versatile platform for hydrazine monitoring in biological and environmental settings.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127479"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-19DOI: 10.1016/j.saa.2026.127495
Maciej Roman , Tomasz P. Wrobel , Agnieszka Panek , Danuta Liberda-Matyja , Wojciech M. Kwiatek
Radiotherapy is an effective type of anticancer treatment due to its localized impact and fewer side effects. Nowadays, proton therapy has become a more common choice than photon-based radiotherapy due to its advantages, including independence from tumor oxygen supply and the deposition of energy at the end of the penetration path (the Bragg curve). However, the benefits of radiotherapy are limited by the radioresistance of the irradiated cells. Several approaches have been proposed to overcome this limitation, including the use of radiosensitizers – molecules that selectively increase the damaging effects of irradiation on cancer cells. This kind of combined therapy (chemoradiotherapy) improves the anticancer treatment efficiency, increasing the patient's survival rate. However, biochemical changes induced in cancer cells by chemoradiotherapy are still unexplored at the submicroscale. In this study, Raman microspectroscopy was employed to monitor such changes in radioresistant prostate cancer cells exposed to proton therapy and a combined treatment of protons and selected radiosensitizers (C75, silibinin). Since the irradiation-induced effects are very weak, the analysis was supported by statistical methods (Partial Least Squares Regression, Random Forest classification). Our results reveal an overall cell response to proton therapy similar to that of X-ray treatment. However, a detailed analysis indicated a different protein-to-nucleic acids ratio between these types of radiotherapy. Finally, the chemometric analysis suggests clear differences in cell response to chemo-, radio-, and chemoradiotherapy, which has been confirmed by high output from Random Forest classification.
{"title":"Effect of proton therapy and chemoradiotherapy on biochemistry of radioresistant prostate cancer cells studied by Raman microspectroscopy","authors":"Maciej Roman , Tomasz P. Wrobel , Agnieszka Panek , Danuta Liberda-Matyja , Wojciech M. Kwiatek","doi":"10.1016/j.saa.2026.127495","DOIUrl":"10.1016/j.saa.2026.127495","url":null,"abstract":"<div><div>Radiotherapy is an effective type of anticancer treatment due to its localized impact and fewer side effects. Nowadays, proton therapy has become a more common choice than photon-based radiotherapy due to its advantages, including independence from tumor oxygen supply and the deposition of energy at the end of the penetration path (the Bragg curve). However, the benefits of radiotherapy are limited by the radioresistance of the irradiated cells. Several approaches have been proposed to overcome this limitation, including the use of radiosensitizers – molecules that selectively increase the damaging effects of irradiation on cancer cells. This kind of combined therapy (chemoradiotherapy) improves the anticancer treatment efficiency, increasing the patient's survival rate. However, biochemical changes induced in cancer cells by chemoradiotherapy are still unexplored at the submicroscale. In this study, Raman microspectroscopy was employed to monitor such changes in radioresistant prostate cancer cells exposed to proton therapy and a combined treatment of protons and selected radiosensitizers (C75, silibinin). Since the irradiation-induced effects are very weak, the analysis was supported by statistical methods (Partial Least Squares Regression, Random Forest classification). Our results reveal an overall cell response to proton therapy similar to that of X-ray treatment. However, a detailed analysis indicated a different protein-to-nucleic acids ratio between these types of radiotherapy. Finally, the chemometric analysis suggests clear differences in cell response to chemo-, radio-, and chemoradiotherapy, which has been confirmed by high output from Random Forest classification.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127495"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-12DOI: 10.1016/j.saa.2026.127468
Yuwei Pan , Xiaoyan Deng , Rong Zhang , Liuyan You , Jiaqing Guo , Youxiu Lin , Dianping Tang , Wenqiang Lai
Early and accessible detection of tumor biomarkers requires robust colorimetric readouts that can operate in complex matrices. We report flower-like hierarchical FeMoO4 nanoparticles functioning as a peroxidase-like nanozyme and enable a cascade immunoassay for carcinoembryonic antigen. The nanoparticles were obtained by a solvothermal route and exhibit a single crystalline FeMoO4 phase with uniform Fe, Mo, and O distributions, mixed Fe3+ and Fe2+ states, and a measurable fraction of surface non-lattice oxygen species (O_ads, including hydroxyl-related oxygen and adsorbed/weakly bound oxygen). These features support efficient H2O2 activation and TMB oxidation. FeMoO4 was integrated with a glucose oxidase (GOx)-based enzyme signal reporter, in which GOx and the detection antibody (Ab2) were co-immobilized on gold nanoparticles (AuNPs) to form GOx-AuNP-Ab2 conjugate. In a sandwich immunoassay format, the captured enzyme-labeled conjugate generates H2O2 in proportion to the antigen concentration, which is subsequently converted by FeMoO4 into a stable colorimetric signal at 652 nm. Reaction conditions were optimized for both the chromogenic branch and the enzymatic branch, and kinetic analysis gave Michaelis-Menten behavior with Km values of 0.78 mM for H2O2 and 0.40 mM for TMB. Radical scavenging identified superoxide and hydroxyl radicals as the main active species, with singlet oxygen as a minor contributor. The CEA assay achieved a linear range of 0.1 to 60 ng mL−1 and a limit of detection of 63 pg mL−1, with a one month retention of 93% of the initial absorbance. Results for six clinical serum samples showed good agreement with a commercial ELISA at the 95% confidence level, and one CEA-negative serum was included as a negative control. These findings establish FeMoO4 as a stable and manufacturable nanozyme platform for colorimetric immunoassays.
早期和可获得的肿瘤生物标志物检测需要强大的比色读数，可以在复杂的基质中操作。我们报道了花状分层的FeMoO4纳米颗粒作为过氧化物酶样纳米酶的功能，并使癌胚抗原的级联免疫测定成为可能。通过溶剂热法获得纳米颗粒，呈现出Fe、Mo和O均匀分布的单晶FeMoO4相，Fe3+和Fe2+混合态，表面非晶格氧（O_ads，包括羟基相关氧和吸附/弱结合氧）的可测量分数。这些特性支持高效的H2O2活化和TMB氧化。FeMoO4与基于葡萄糖氧化酶（GOx）的酶信号报告蛋白结合，将GOx与检测抗体（Ab2）共固定在金纳米颗粒（AuNPs）上，形成GOx- aunp -Ab2偶联物。在三明治免疫分析中，捕获的酶标记的偶联物与抗原浓度成比例地产生H2O2，随后由FeMoO4在652nm处转化为稳定的比色信号。对显色分支和酶促分支的反应条件进行了优化，动力学分析表明，H2O2和TMB的Km值分别为0.78 mM和0.40 mM，具有Michaelis-Menten行为。自由基清除鉴定超氧自由基和羟基自由基是主要的活性物种，单线态氧是次要的贡献者。CEA测定的线性范围为0.1 ~ 60 ng mL - 1，检测限为63 pg mL - 1，一个月的保留率为初始吸光度的93%。6份临床血清样本的结果与商用ELISA在95%的置信水平上吻合良好，并将1份cea阴性血清作为阴性对照。这些发现表明，FeMoO4是一种稳定的、可制造的纳米酶平台，可用于比色免疫测定。
{"title":"Flower-like FeMoO4 nanoparticles as a peroxidase mimic for sensitive colorimetric immunoassay of CEA","authors":"Yuwei Pan , Xiaoyan Deng , Rong Zhang , Liuyan You , Jiaqing Guo , Youxiu Lin , Dianping Tang , Wenqiang Lai","doi":"10.1016/j.saa.2026.127468","DOIUrl":"10.1016/j.saa.2026.127468","url":null,"abstract":"<div><div>Early and accessible detection of tumor biomarkers requires robust colorimetric readouts that can operate in complex matrices. We report flower-like hierarchical FeMoO<sub>4</sub> nanoparticles functioning as a peroxidase-like nanozyme and enable a cascade immunoassay for carcinoembryonic antigen. The nanoparticles were obtained by a solvothermal route and exhibit a single crystalline FeMoO<sub>4</sub> phase with uniform Fe, Mo, and O distributions, mixed Fe<sup>3+</sup> and Fe<sup>2+</sup> states, and a measurable fraction of surface non-lattice oxygen species (O_ads, including hydroxyl-related oxygen and adsorbed/weakly bound oxygen). These features support efficient H<sub>2</sub>O<sub>2</sub> activation and TMB oxidation. FeMoO<sub>4</sub> was integrated with a glucose oxidase (GOx)-based enzyme signal reporter, in which GOx and the detection antibody (Ab2) were co-immobilized on gold nanoparticles (AuNPs) to form GOx-AuNP-Ab2 conjugate. In a sandwich immunoassay format, the captured enzyme-labeled conjugate generates H<sub>2</sub>O<sub>2</sub> in proportion to the antigen concentration, which is subsequently converted by FeMoO<sub>4</sub> into a stable colorimetric signal at 652 nm. Reaction conditions were optimized for both the chromogenic branch and the enzymatic branch, and kinetic analysis gave Michaelis-Menten behavior with <em>K</em><sub>m</sub> values of 0.78 mM for H<sub>2</sub>O<sub>2</sub> and 0.40 mM for TMB. Radical scavenging identified superoxide and hydroxyl radicals as the main active species, with singlet oxygen as a minor contributor. The CEA assay achieved a linear range of 0.1 to 60 ng mL<sup>−1</sup> and a limit of detection of 63 pg mL<sup>−1</sup>, with a one month retention of 93% of the initial absorbance. Results for six clinical serum samples showed good agreement with a commercial ELISA at the 95% confidence level, and one CEA-negative serum was included as a negative control. These findings establish FeMoO<sub>4</sub> as a stable and manufacturable nanozyme platform for colorimetric immunoassays.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127468"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, Raman and Infrared spectroscopy have become important tools in disease diagnosis due to their high sensitivity and non-invasive detection advantages. Combined with deep learning methods, spectral data can achieve high-precision identification of a wide range of diseases. However, deep learning models rely on large amounts of high-quality data. In practice, spectral data often faces challenges such as limited sample size, noise interference, and device variability, leading to model overfitting and poor generalization. To overcome this bottleneck, this paper proposes a spectral data generation method based on a diffusion model. By encoding temporal and category label information separately and combining it with a multi-head attention mechanism, the method extracts the overall morphology and local subtle features of the spectrum at multiple scales. In the reverse reconstruction stage, the noise distribution is estimated based on implicit modeling and cross-attention is used to generate spectra of different categories under different labels. This method achieves accurate denoising under conditional constraints and progressively reconstructs information such as the positions of characteristic spectral peaks. This method generates high-quality, continuous spectral data, effectively enhancing the scale and quality of the dataset. Experimental results demonstrate that the proposed method can generate high-fidelity and diverse synthetic spectral samples. The Pearson correlation coefficients for the thyroid and SLE infrared datasets reached high values of 0.97719 and 0.9914, respectively, and the similarities for the Thyroid and SLE Raman datasets reached high values of 0.9531 and 0.9747, respectively. This method effectively expands the training dataset and alleviates data scarcity and uneven distribution. The diffusion model was applied to two disease diagnosis tasks for validation. Under the condition of optimal gain ratio,the model trained with augmented data significantly improved generalization performance and diagnostic accuracy. In the infrared spectroscopy classification task, the accuracy of SLE disease on EfficientNet improved from 69.70% to 90.91%, and the accuracy of benign and malignant thyroid tumors on EfficientNet improved from 66.67% to 89.47%. In the Raman spectroscopy classification task, the accuracy of SLE disease on MLP improved from 87.88% to 90.91%, and the accuracy of benign and malignant thyroid tumors on the Transformer model improved from 87.22% to 92.98%.This study provides an effective generative augmentation framework for small-sample spectral data analysis, with strong theoretical value and application prospects.
{"title":"A research on applying the diffusion model algorithm for Infrared and Raman spectroscopy data augmentation to improve the accuracy of diseases","authors":"Xiangnan Chen , Cheng Chen , Xuguang Zhou , Xiaoyi Lv , Chen Chen","doi":"10.1016/j.saa.2026.127466","DOIUrl":"10.1016/j.saa.2026.127466","url":null,"abstract":"<div><div>In recent years, Raman and Infrared spectroscopy have become important tools in disease diagnosis due to their high sensitivity and non-invasive detection advantages. Combined with deep learning methods, spectral data can achieve high-precision identification of a wide range of diseases. However, deep learning models rely on large amounts of high-quality data. In practice, spectral data often faces challenges such as limited sample size, noise interference, and device variability, leading to model overfitting and poor generalization. To overcome this bottleneck, this paper proposes a spectral data generation method based on a diffusion model. By encoding temporal and category label information separately and combining it with a multi-head attention mechanism, the method extracts the overall morphology and local subtle features of the spectrum at multiple scales. In the reverse reconstruction stage, the noise distribution is estimated based on implicit modeling and cross-attention is used to generate spectra of different categories under different labels. This method achieves accurate denoising under conditional constraints and progressively reconstructs information such as the positions of characteristic spectral peaks. This method generates high-quality, continuous spectral data, effectively enhancing the scale and quality of the dataset. Experimental results demonstrate that the proposed method can generate high-fidelity and diverse synthetic spectral samples. The Pearson correlation coefficients for the thyroid and SLE infrared datasets reached high values of 0.97719 and 0.9914, respectively, and the similarities for the Thyroid and SLE Raman datasets reached high values of 0.9531 and 0.9747, respectively. This method effectively expands the training dataset and alleviates data scarcity and uneven distribution. The diffusion model was applied to two disease diagnosis tasks for validation. Under the condition of optimal gain ratio,the model trained with augmented data significantly improved generalization performance and diagnostic accuracy. In the infrared spectroscopy classification task, the accuracy of SLE disease on EfficientNet improved from 69.70% to 90.91%, and the accuracy of benign and malignant thyroid tumors on EfficientNet improved from 66.67% to 89.47%. In the Raman spectroscopy classification task, the accuracy of SLE disease on MLP improved from 87.88% to 90.91%, and the accuracy of benign and malignant thyroid tumors on the Transformer model improved from 87.22% to 92.98%.This study provides an effective generative augmentation framework for small-sample spectral data analysis, with strong theoretical value and application prospects.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127466"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146013913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-15Epub Date: 2026-01-21DOI: 10.1016/j.saa.2026.127502
Dan Wang , Zixin Wu , Tianyu Song , Qunfang Li , Cuiling Zeng , You Wang , Xiaosu Fan , Pengyun Liang
Mercury ion (Hg2+) pollution poses severe environmental and health risks, necessitating the development of highly sensitive and reliable detection methods. Although ratiometric and genetically encoded fluorescent probes each offer distinct advantages, their integration for Hg2+ sensing remains largely unexplored. Herein, we report the rational design of a novel ratiometric genetically encoded fluorescent probe through the fusion of a circularly permuted green fluorescent protein (cpEGFP), a mercury-binding domain (MerBD), and a large Stokes shift reference fluorescent protein (LSSmOrange). This probe enables self-calibrated Hg2+ quantification by measuring the fluorescence intensity ratio of the response channel (F512) to the stable reference channel (F572), which effectively minimizes interferences from probe concentration, environmental fluctuations, and instrumental variations. The probe exhibits an ultra-high affinity for Hg2+ (apparent Kd' = 2.71 × 10−13 M) and a detection limit of 4 nM, alongside long-term stability and high selectivity against most common metal ions. Competitive titration, circular dichroism, and fluorescence lifetime analyses reveal that the probe operates through a cooperative conformational-change mechanism, which translates picomolar-level binding into a nanomolar-level fluorescence response. This work not only addresses a critical gap in ratiometric genetically encoded probes for Hg2+ but also provides a robust and versatile platform for accurate Hg2+ monitoring in environmental and biological systems.
{"title":"A Ratiometric genetically encoded fluorescent probe for ultrasensitive and self-calibrated detection of Hg2+","authors":"Dan Wang , Zixin Wu , Tianyu Song , Qunfang Li , Cuiling Zeng , You Wang , Xiaosu Fan , Pengyun Liang","doi":"10.1016/j.saa.2026.127502","DOIUrl":"10.1016/j.saa.2026.127502","url":null,"abstract":"<div><div>Mercury ion (Hg<sup>2+</sup>) pollution poses severe environmental and health risks, necessitating the development of highly sensitive and reliable detection methods. Although ratiometric and genetically encoded fluorescent probes each offer distinct advantages, their integration for Hg<sup>2+</sup> sensing remains largely unexplored. Herein, we report the rational design of a novel ratiometric genetically encoded fluorescent probe through the fusion of a circularly permuted green fluorescent protein (cpEGFP), a mercury-binding domain (MerBD), and a large Stokes shift reference fluorescent protein (LSSmOrange). This probe enables self-calibrated Hg<sup>2+</sup> quantification by measuring the fluorescence intensity ratio of the response channel (F<sub>512</sub>) to the stable reference channel (F<sub>572</sub>), which effectively minimizes interferences from probe concentration, environmental fluctuations, and instrumental variations. The probe exhibits an ultra-high affinity for Hg<sup>2+</sup> (apparent K<sub>d</sub>' = 2.71 × 10<sup>−13</sup> M) and a detection limit of 4 nM, alongside long-term stability and high selectivity against most common metal ions. Competitive titration, circular dichroism, and fluorescence lifetime analyses reveal that the probe operates through a cooperative conformational-change mechanism, which translates picomolar-level binding into a nanomolar-level fluorescence response. This work not only addresses a critical gap in ratiometric genetically encoded probes for Hg<sup>2+</sup> but also provides a robust and versatile platform for accurate Hg<sup>2+</sup> monitoring in environmental and biological systems.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"351 ","pages":"Article 127502"},"PeriodicalIF":4.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146055791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-04-05Epub Date: 2026-01-04DOI: 10.1016/j.saa.2026.127431
Suyu Li, Yuzhen Wang, Huilin Liu, Baoguo Sun
To enable accurate visual identification of organophosphorus pesticides (OPs) in raw materials of medicinal and food homology (MFH), this study used the red-fluorescent covalent organic polymer TEPBY-DTDA to cascade MnO2 nanosheets exhibiting oxidase-mimetic activity and suppressing fluorescence effects, enabling colorimetric and ratiometric fluorescence detection. OPs suppressed acetylcholinesterase (AChE) efficiency, consequently diminishing thiocholine (TCh) production and modulating residual MnO2 nanosheet levels. Rising OP concentrations caused the probe's fluorescence to shift red-to-yellow, accompanied by solution yellowing. Using triazophos, methyl parathion (MP), chlorpyrifos, and phoxim as representative OPs, the probes generated a robust, linear signal over the concentration interval of 0.1–1500 μg/L. The fluorescence minimal limit of detection (LOD) was 0.058 μg/L, while the minimum LOD in colorimetric mode was 0.04 μg/L. The probe demonstrated excellent selectivity and strong anti-interference capability against OPs. Consequently, this sensing strategy not only expands the toolbox for quality monitoring of MFH materials but also holds significant potential for enhancing food safety protocols.
{"title":"Covalent organic polymer cascade MnO2 nanosheets-based fluorescence-colorimetric dual-mode sensing system for highly sensitive detection of organophosphorus pesticides","authors":"Suyu Li, Yuzhen Wang, Huilin Liu, Baoguo Sun","doi":"10.1016/j.saa.2026.127431","DOIUrl":"10.1016/j.saa.2026.127431","url":null,"abstract":"<div><div>To enable accurate visual identification of organophosphorus pesticides (OPs) in raw materials of medicinal and food homology (MFH), this study used the red-fluorescent covalent organic polymer TEPBY-DTDA to cascade MnO<sub>2</sub> nanosheets exhibiting oxidase-mimetic activity and suppressing fluorescence effects<strong>,</strong> enabling colorimetric and ratiometric fluorescence detection. OPs suppressed acetylcholinesterase (AChE) efficiency, consequently diminishing thiocholine (TCh) production and modulating residual MnO<sub>2</sub> nanosheet levels. Rising OP concentrations caused the probe's fluorescence to shift red-to-yellow, accompanied by solution yellowing. Using triazophos, methyl parathion (MP), chlorpyrifos, and phoxim as representative OPs, the probes generated a robust, linear signal over the concentration interval of 0.1–1500 μg/L. The fluorescence minimal limit of detection (LOD) was 0.058 μg/L, while the minimum LOD in colorimetric mode was 0.04 μg/L. The probe demonstrated excellent selectivity and strong anti-interference capability against OPs. Consequently, this sensing strategy not only expands the toolbox for quality monitoring of MFH materials but also holds significant potential for enhancing food safety protocols.</div></div>","PeriodicalId":433,"journal":{"name":"Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy","volume":"350 ","pages":"Article 127431"},"PeriodicalIF":4.6,"publicationDate":"2026-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145936380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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