Microchimica Acta最新文献_第9页

Development of a syringe-hosted load-and-read immunoassay device using autoinjected distance readout in paper inserts

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-28 DOI: 10.1007/s00604-025-07052-w

Haojie Li, Jie Liu, Cuili Li, Runze Wang, Sapna Kannan, XiuJun Li, Guanglei Fu

Pressure-based signal readout is promising for developing instrument-free immunoassays, but new detection methods are desirable to further advance the applicability of point-of-care testing (POCT). Herein, we developed a syringe-hosted load-and-read immunoassay device using autoinjected distance readout in paper inserts. The device was composed of multiple disposable syringes as the host for immuno-recognition, a three-dimensional (3D)-printed loading magazine of the syringes, and paper inserts to the magazine for distance signal readout. Using prostate-specific antigen (PSA) as a model target, the immuno-recognition system was constructed on the inner cylinder walls of the syringes. The immuno-captured platinum nanoparticles (Pt NPs) catalyzed the decomposition of H₂O₂ to produce O₂ in the cylinders, driving the automatic quantitative injection behavior of the syringes. By loading the syringes into the magazine, the autoinjected liquids were received by the paper inserts to display the immunoassay signals as a visual traveling distance of liquids. PSA was determined with a low limit of detection (LOD) of 0.32 ng/mL and high accuracy in testing clinical serum specimens. Given the advantages of the simple syringe-hosted immuno-recognition method and the load-and-read signal readout in the paper inserts, the immunoassay device shows great potential in POCT.

Graphical abstract

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引用次数: 0

A colorimetric/SERS dual-mode sensor based on ferric ion-dopamine@Au–Ag-Au Janus NPs for acrylamide determination in baked goods

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-27 DOI: 10.1007/s00604-025-07051-x

Yutong Wang, Yizhi Liu, Xiao Liang, Zhiyuan Liu, Yaling Yang

This study successfully developed a colorimetric/SERS dual-mode sensor for determining acrylamide in baked goods based on the excellent peroxidase-like activity and Raman activity of Fe-PHS@Au–Ag-Au Janus NPs. In colorimetric mode, the thiol-ene Michael addition between acrylamide (AA) and glutathione (GSH) efficiently eliminates GSH-induced peroxidase-like activity inhibition. The peroxidase-like activity of Fe-PHS@Au–Ag-Au Janus NPs gradually recovered, and the blue color of the solution gradually deepened with the increase in AA dosage. In surface-enhanced Raman spectroscopy (SERS), Apt-Fe-PHS@Au–Ag-Au Janus NPs can selectively capture AA and bind specifically, leading to the dissociation of Apt and Fe-PHS@Au–Ag-Au Janus NPs. The Raman activity of Apt-Fe-PHS@Au–Ag-Au Janus NPs decreases due to the dissociation of Apt. The dual-mode sensor was utilized for the determination of acrylamide in the concentrations range from 0.05 to 20 µg·L⁻¹ with detection limits of 0.06 µg·L⁻¹ (SERS) and 0.01 µg·L⁻¹ (colorimetric). The recovery in baked samples was between 91.0 and 108.0%.

Graphical Abstract

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引用次数: 0

Magnetic rod-shaped Mn-based MOF as a multi-functional and recyclable platform for dual-mode ratiometric-based nitrite detection

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-27 DOI: 10.1007/s00604-025-07054-8

Sameera Sh. Mohammed Ameen, Faisal Algethami, Khalid M. Omer

The development is shown of rod-shaped manganese-based metal–organic frameworks (Mn-MOFs) as hot- and cold-adapted oxidase-like nanozymes, with strong magnetic properties. These Mn-MOFs enable highly sensitive detection of nitrite ions, utilizing both convenient colorimetric ratio analysis and a visual instrument-free-based approach compatible with smartphone-based detection. The Mn-MOF showed multi-functional activity, such as cold/hot-adapted and magnetic oxidase-like activity, catalyzing the oxidation of chromogenic substrates 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB). Mn-MOF shows high oxidase activity with Vmax of 1.39 × 10⁻⁸ M/s and Km of 0.068 mM for TMB oxidation. Nitrite ions further react with oxTMB to form a yellow color via diazotization resulting in the ratiometric change in absorbance (A₆₅₂/A₄₆₁). The color ratio is also quantified through the naked eye and/or smartphone app by analyzing RGB values, providing a rapid, portable, and cost-effective method for on-site detection. When applying Mn-MOF for smartphone-based nitrite detection, it performs excellent detection, with a linear range of 5.0–55.0 µM and a limit of detection of 0.18 µM, superior to most of the oxidase nanozyme-based nitrite sensing platforms. The detection platforms develop sensing probes using a reusable nanozyme that enables highly sensitive and selective detection of nitrite, featuring a broad linear range and a low limit of detection.

Graphical Abstract

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引用次数: 0

A core-satellite self-assembled SERS aptasensor used for ultrasensitive detection of AFB1

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-26 DOI: 10.1007/s00604-025-07040-0

Danni Sun, Tao Liu, Yiran Yao, Dezhao Kong, Chang Liu, Hua Ye, Qi Zhang, Shijie Li, Yaqi Li, Qiaoqiao Shi

A surface-enhanced Raman scattering (SERS) aptasensor was developed using gold nanostars (Au NSs) and Fe₃O₄@Au nanoparticles (NPs) for the highly sensitive detection of aflatoxin B₁ (AFB₁). Au NSs were modified by the Raman reporter 4-aminothiophenol (PATP) and then coupled with cDNA to act as the capture probes (Au NSs@PATP-cDNA). Fe₃O₄@Au NPs were modified with the AFB₁ aptamer (AFB₁ Apt) and used as signal probes (Fe₃O₄@Au NPs-AFB₁ Apt). The SERS peak of PATP at 1078 cm⁻¹ was used for quantitative analysis. When the core-satellite nanostructures (Fe₃O₄@Au NPs-AFB₁ Apt/cDNA-Au NSs@PATP) were self-assembled by oligonucleotide hybridization, the SERS intensity was significantly enhanced. When AFB₁ was present, AFB₁ Apt specifically binds to AFB₁, causing the Fe₃O₄@Au NPs-AFB₁ Apt and Au NSs@PATP-cDNA to dissociate, resulting in a decrease in the SERS intensity measured after magnetic separation. Under optimal conditions, the limit of detection (LOD) of AFB₁ can be reduced to 0.24 pg/mL. This is attributed to the high affinity of AFB₁ Apt, excellent magnetic separation characteristics, and multiple SERS hotspots. The assay has been validated to perform well in recovery and accuracy by evaluating spiked samples (rice, corn, and wheat) and positive samples (corn, brown rice, and wheat).

Graphical Abstract

{"title":"A core-satellite self-assembled SERS aptasensor used for ultrasensitive detection of AFB1","authors":"Danni Sun, Tao Liu, Yiran Yao, Dezhao Kong, Chang Liu, Hua Ye, Qi Zhang, Shijie Li, Yaqi Li, Qiaoqiao Shi","doi":"10.1007/s00604-025-07040-0","DOIUrl":"10.1007/s00604-025-07040-0","url":null,"abstract":"<div><p>A surface-enhanced Raman scattering (SERS) aptasensor was developed using gold nanostars (Au NSs) and Fe<sub>3</sub>O<sub>4</sub>@Au nanoparticles (NPs) for the highly sensitive detection of aflatoxin B<sub>1</sub> (AFB<sub>1</sub>). Au NSs were modified by the Raman reporter 4-aminothiophenol (PATP) and then coupled with cDNA to act as the capture probes (Au NSs@PATP-cDNA). Fe<sub>3</sub>O<sub>4</sub>@Au NPs were modified with the AFB<sub>1</sub> aptamer (AFB<sub>1</sub> Apt) and used as signal probes (Fe<sub>3</sub>O<sub>4</sub>@Au NPs-AFB<sub>1</sub> Apt). The SERS peak of PATP at 1078 cm<sup>−1</sup> was used for quantitative analysis. When the core-satellite nanostructures (Fe<sub>3</sub>O<sub>4</sub>@Au NPs-AFB<sub>1</sub> Apt/cDNA-Au NSs@PATP) were self-assembled by oligonucleotide hybridization, the SERS intensity was significantly enhanced. When AFB<sub>1</sub> was present, AFB<sub>1</sub> Apt specifically binds to AFB<sub>1</sub>, causing the Fe<sub>3</sub>O<sub>4</sub>@Au NPs-AFB<sub>1</sub> Apt and Au NSs@PATP-cDNA to dissociate, resulting in a decrease in the SERS intensity measured after magnetic separation. Under optimal conditions, the limit of detection (LOD) of AFB<sub>1</sub> can be reduced to 0.24 pg/mL. This is attributed to the high affinity of AFB<sub>1</sub> Apt, excellent magnetic separation characteristics, and multiple SERS hotspots. The assay has been validated to perform well in recovery and accuracy by evaluating spiked samples (rice, corn, and wheat) and positive samples (corn, brown rice, and wheat).</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":705,"journal":{"name":"Microchimica Acta","volume":"192 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496817","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}

引用次数: 0

A novel photoelectrochemical strategy for ultrasensitive and simultaneous detection of 5-methylcytosine and N6-methyladenosine based on proximity binding-triggered assembly MNAzyme -mediated HRCA

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-26 DOI: 10.1007/s00604-025-07033-z

Yue Hu, Mengshi Xia, Mimi Li, Lulu Li, Chenghong Li, Yi Liu, Lina Wang, Hui Huang, Lichao Fang, Kexing Peng, Huamin Liu, Xiaolong Wang, Junsong Zheng

The preparation of UiO-66@CdTe@AuNPs composites is presented for the first time, which function as a photoelectrochemical (PEC) sensing matrix and are conjugated to a three-way junction (TWJ). We propose an antibody-based specific recognition-induced neighbor-joining reaction that initiates the assembly of two molecularly designed nucleic acid enzymes (MNAzymes), to release an oligonucleotide that hydrolyzes TWJ through the mechanism of a toehold-mediated strand displacement reaction (TSDR). Subsequently, a hybridization chain reaction application (HRCA)-based dendrimer is formed, which immobilizes a large number of quantum dots to generate a burst effect that reduces the photocurrent signal. As anticipated, the developed PEC biosensor showed excellent analytical performance for both m⁶A-RNA and m⁵C-RNA, with detection limits of 0.309 fM and 6.918 aM, respectively. The successful fabrication of this ultrasensitive and simultaneous PEC biosensor provides new insights for epigenetic research and the bioassay, mechanism investigation and clinical diagnosis of diseases associated with RNA methylation.

Graphical Abstract

{"title":"A novel photoelectrochemical strategy for ultrasensitive and simultaneous detection of 5-methylcytosine and N6-methyladenosine based on proximity binding-triggered assembly MNAzyme -mediated HRCA","authors":"Yue Hu, Mengshi Xia, Mimi Li, Lulu Li, Chenghong Li, Yi Liu, Lina Wang, Hui Huang, Lichao Fang, Kexing Peng, Huamin Liu, Xiaolong Wang, Junsong Zheng","doi":"10.1007/s00604-025-07033-z","DOIUrl":"10.1007/s00604-025-07033-z","url":null,"abstract":"<div><p> The preparation of UiO-66@CdTe@AuNPs composites is presented for the first time, which function as a photoelectrochemical (PEC) sensing matrix and are conjugated to a three-way junction (TWJ). We propose an antibody-based specific recognition-induced neighbor-joining reaction that initiates the assembly of two molecularly designed nucleic acid enzymes (MNAzymes), to release an oligonucleotide that hydrolyzes TWJ through the mechanism of a toehold-mediated strand displacement reaction (TSDR). Subsequently, a hybridization chain reaction application (HRCA)-based dendrimer is formed, which immobilizes a large number of quantum dots to generate a burst effect that reduces the photocurrent signal. As anticipated, the developed PEC biosensor showed excellent analytical performance for both m<sup>6</sup>A-RNA and m<sup>5</sup>C-RNA, with detection limits of 0.309 fM and 6.918 aM, respectively. The successful fabrication of this ultrasensitive and simultaneous PEC biosensor provides new insights for epigenetic research and the bioassay, mechanism investigation and clinical diagnosis of diseases associated with RNA methylation. </p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":705,"journal":{"name":"Microchimica Acta","volume":"192 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496818","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}

引用次数: 0

Simple graphite/PVC ink-designed paper-based electrodes integrated with a 3D-printed electrochemical device for affordable analyses

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-26 DOI: 10.1007/s00604-025-07041-z

Gleidson Thiago Sá Araújo, Lucas Costa Faustino, Rejane Maria Pereira Silva, Welter Cantanhêde, Everson Thiago Santos Gerôncio

A simple and cost-effective methodology for manufacturing a portable electroanalytical device is reported. The device is based on a graphite/polyvinyl chloride (PVC) paper-based electrode coupled to a miniaturized 3D-printed electrochemical cell (3DEC). The 3DEC was designed to ensure the reproducibility of the system by delimitating the paper-based graphite electrode (PGE) area. The disposable PGE was fabricated by paint-brushing a conductive ink based on graphite powder and toluene-free PVC glue, onto a kraft paper. Different weight proportions (wt%) of graphite/PVC were evaluated regarding mechanical stability and electrochemical behavior. Cyclic voltammetric (CV) analysis in the presence of the [Fe(CN)₆]^3−/4− redox probe has shown that as the wt% of graphite in the ink increased from 50 to 90%, a clear decrease in peak potential separation (ΔE_p) and increase in current are observed, indicating an improvement in charge transfer kinetics. However, 90 wt% graphite electrodes have shown poor adhesion to the substrate and easy leaching due to the small amount of PVC (binder). Therefore, the best PGE was achieved using 80:20 wt% graphite/PVC ink (PGE8020). Moreover, scanning electron microscopy (SEM) images and energy dispersive spectroscopy (EDS) mapping revealed a rugous and more uniform deposition of the conductive ink containing 80 wt% graphite. As a proof of concept, the graphite/PVC ink-based disposable electrodes were employed for the detection of 3-nitro-L-tyrosine (3-NLT) in synthetic urine samples, showing a detection limit of 2.85 μmol L⁻¹, and %recovery in synthetic urine between 97 and 109%, highlighting the reliability and applicability of the proposed approach.

Graphical Abstract

{"title":"Simple graphite/PVC ink-designed paper-based electrodes integrated with a 3D-printed electrochemical device for affordable analyses","authors":"Gleidson Thiago Sá Araújo, Lucas Costa Faustino, Rejane Maria Pereira Silva, Welter Cantanhêde, Everson Thiago Santos Gerôncio","doi":"10.1007/s00604-025-07041-z","DOIUrl":"10.1007/s00604-025-07041-z","url":null,"abstract":"<div><p> A simple and cost-effective methodology for manufacturing a portable electroanalytical device is reported. The device is based on a graphite/polyvinyl chloride (PVC) paper-based electrode coupled to a miniaturized 3D-printed electrochemical cell (3DEC). The 3DEC was designed to ensure the reproducibility of the system by delimitating the paper-based graphite electrode (PGE) area. The disposable PGE was fabricated by paint-brushing a conductive ink based on graphite powder and toluene-free PVC glue, onto a kraft paper. Different weight proportions (wt%) of graphite/PVC were evaluated regarding mechanical stability and electrochemical behavior. Cyclic voltammetric (CV) analysis in the presence of the [Fe(CN)<sub>6</sub>]<sup>3−/4−</sup> redox probe has shown that as the wt% of graphite in the ink increased from 50 to 90%, a clear decrease in peak potential separation (Δ<i>E</i><sub>p</sub>) and increase in current are observed, indicating an improvement in charge transfer kinetics. However, 90 wt% graphite electrodes have shown poor adhesion to the substrate and easy leaching due to the small amount of PVC (binder). Therefore, the best PGE was achieved using 80:20 wt% graphite/PVC ink (PGE8020). Moreover, scanning electron microscopy (SEM) images and energy dispersive spectroscopy (EDS) mapping revealed a rugous and more uniform deposition of the conductive ink containing 80 wt% graphite. As a proof of concept, the graphite/PVC ink-based disposable electrodes were employed for the detection of 3-nitro-L-tyrosine (3-NLT) in synthetic urine samples, showing a detection limit of 2.85 μmol L<sup>−1</sup>, and %recovery in synthetic urine between 97 and 109%, highlighting the reliability and applicability of the proposed approach.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":705,"journal":{"name":"Microchimica Acta","volume":"192 3","pages":""},"PeriodicalIF":5.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496823","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}

引用次数: 0

Ratiometric fluorescence sensor for Escherichia coli detection using fluorescein isothiocyanate–labeled metal–organic frameworks

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-25 DOI: 10.1007/s00604-025-07053-9

Duoduo Zhang, Xinyu Zhang, Mingshuang Liang, Xiuxiu Li, Heping Xiao, Dawei Cao, Xiubo Zhao

A ratiometric fluorescence sensor for detecting Escherichia coli (E. coli) was fabricated based on the fluorescein isothiocyanate (FITC)–labeled zirconium (Zr)–tetraphenylporphyrin tetrasulfonic acid (TPPS) hydrate metal–organic frameworks (ZTMs@FITC). The ZTMs have strong red fluorescence emission at 683 nm, which can be quenched by Cu²⁺. E. coli can capture and convert external Cu²⁺ into Cu⁺ through its distinctive metabolic activities. To minimize environmental and instrumental influences and enhance detection precision, green FITC with an emission peak at 515 nm was utilized as the fluorescence labeling agent to fabricate the ratiometric fluorescence probe (ZTMs@FITC). The prepared ZTMs@FITC probe showed excellent performance in the detection of E. coli. As the concentration of E. coli increased, the fluorescence intensity at 683 nm (ZTMs, F₆₈₃) increased considerably, while the fluorescence intensity at 515 nm (FITC, F₅₁₅) decreased. By monitoring the increase in the ratio of F₆₈₃ to F₅₁₅, this sensor achieved rapid and sensitive detection of E. coli within the concentration range from 1.0 × 10¹ to 5.0 × 10⁵ CFU/mL. The limit of detection was 6 CFU/mL. When observed under a 365 nm ultraviolet lamp, the fluorescence color of the solution changed from yellow to red. Additionally, the dual-signal ratiometric fluorescence method exhibited high selectivity for E. coli and was successfully utilized to detect E. coli in juice samples, demonstrating its practical application potential in food analysis.

Graphical Abstract

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引用次数: 0

Multicomponent nucleic acid enzymes as signal amplification strategy for the detection of microRNA based on fluorescence resonance energy transfer

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-25 DOI: 10.1007/s00604-025-07002-6

Adrián Sánchez-Visedo, Patricia Alcázar-González, Luis José Royo, Ana Soldado, Francisco Javier Ferrero, José Manuel Costa-Fernández, María Teresa Fernández-Argüelles

A novel and simple methodology is introduced that allows accurate and highly sensitive detection of microRNAs (miRNAs), taking advantage of an amplification strategy based on multicomponent nucleic acid enzymes (MNAzymes), combined with a fluorescence resonance energy transfer (FRET) phenomenon. For this purpose, a fluorescent dye (FAM) has been selected as an energy donor, while gold nanoparticles (AuNPs) are employed as energy acceptors, located close to each other through hybridisation with the substrate. The research object was miR146a, which is a biomarker whose overexpression in milk is associated with inflammation in bovine mammary glands caused by bovine mastitis. The presence of a genetic target activates the MNAzyme cleavage capability, splitting the substrate into two parts. Hence, the presence of the target increases the distance between donor and acceptor, recovering the quenched fluorescence. Experimental parameters have been optimised, achieving a limit of detection (LOD) of only 2.3 fM (highly competitive as compared to other similar approaches) and a wide linear response range between 15.9 fM and 10 nM. In addition, the proposed methodology allows discriminating miR146a from other similar miRNAs differing in a single base mismatch. Detection of miR146a has been successfully carried out in spiked raw milk samples.

Graphical Abstract

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引用次数: 0

Direct lysis combined with amplification-free CRISPR/Cas12a-SERS genosensor for ultrafast and on-site identification of meat authenticity

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-25 DOI: 10.1007/s00604-024-06932-x

Jianghua Liu, Yu Wang, Xinyue Zhang, Mingquan Huang, Guoliang Li

A novel direct lysis method combined with amplification-free CRISPR/Cas12a-SERS genosensor was for the first time developed to rapidly and sensitively identify meat adulteration. Notably, polystyrene (PS) microspheres, with distinct shrinking and swelling properties, were dexterously employed to encapsulate biological-silent Raman reporter 4-mercaptobenzonitrile (4-MBN) and act as a controlled-release signal probe. Target DNA activated the trans-cleavage activity of CRISPR/Cas12a towards ssDNA linked with PS microsphere to liberate the signal probe, which was able to release numerous Raman reporters after treatment with THF solution, resulting in high signal amplification. Through this platform, trace target DNA was deftly transformed into a sensitive Raman signal and could be on-site determined through a portable Raman equipment. Under optimized conditions, this strategy displayed good linearity in the range 1–450 ng/μL (R² = 0.9943) and favorable sensitivity with limit of detection as low as 0.23 ng/μL without any pre-amplification. Moreover, it exhibited good applicability to on-site identification of commercial meat samples in complicated food matrix. In addition, DNA extraction by direct lysis and amplification-free detection realized ultrafast meat adulteration determination within 35 min from sampling to result. This method possessed great potential in rapid and on-site accurate determination of meat authenticity.

Graphical abstract

我们首次开发了一种新颖的直接裂解方法，结合无扩增的CRISPR/Cas12a-SERS基因传感器，可快速灵敏地识别肉类掺假。值得注意的是，该研究巧妙地利用了具有独特收缩和膨胀特性的聚苯乙烯（PS）微球来封装生物无声拉曼报告物 4-巯基苯甲腈（4-MBN），并将其作为可控释放信号探针。靶DNA激活了CRISPR/Cas12a对与PS微球相连的ssDNA的反式裂解活性，从而释放出信号探针，信号探针经四氢呋喃溶液处理后能够释放出大量拉曼报告物，从而实现高信号放大。通过这一平台，痕量目标 DNA 被巧妙地转化为灵敏的拉曼信号，并可通过便携式拉曼设备进行现场测定。在优化条件下，该方法在 1-450 ng/μL 范围内具有良好的线性关系（R2 = 0.9943），灵敏度高，检测限低至 0.23 ng/μL，无需任何预放大。此外，该方法还非常适用于在复杂的食品基质中对商用肉类样品进行现场鉴定。此外，通过直接裂解提取 DNA 和免扩增检测，实现了超快速肉类掺假检测，从取样到检测结果出来仅需 35 分钟。该方法在快速、现场准确测定肉类真伪方面具有巨大潜力。

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引用次数: 0

Fluorescent/colorimetric dual-mode for detecting of MC-LR using bidirectional RCA coupled with CdTe QDs

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta

Pub Date : 2025-02-25 DOI: 10.1007/s00604-025-06991-8

Weiqing Sun, Xinru Ren, Yijing Xiao, Bowen Li, Qing-ao Pang, Meili Yang, Rui Zhu, Zhiqiang Guo, Jinghua Yu, Jiadong Huang, Yu Wang, Su Liu

A fluorescent/colorimetric dual-mode biosensor was designed using CdTe QDs and CRISPR/Cas for the efficient and ultrasensitive detection of microcystin-leucine-arginine (MC-LR). The biosensor mainly activates the trans-cleavage activity of Cas12a through nucleic acid amplification technology, such as bidirectional rolling circle amplification (B-RCA), to perform signal conversion, release Ag⁺ from the cleaving hairpin, quench QD fluorescence, and perform signal presentation. The biosensor can perform fluorometric and colorimetric detection, enabling rapid field assays. It exhibits enhanced selectivity, increased sensitivity, and greater accuracy. The optimal conditions yield a detection range from 0.05 to 500 nM, with a minimum detectable concentration of 2.137 pM, surpassing the performance of traditional methods. The biosensor can effectively detect MC-LR in actual environmental samples. Overall, this study provided a general detection approach for the application of nucleic acid detection technology to detect trace pollutants in the environment.

Graphical Abstract

利用CdTe QDs和CRISPR/Cas设计了一种荧光/比色双模式生物传感器，用于高效、超灵敏地检测微囊藻毒素-亮氨酸-精氨酸（MC-LR）。该生物传感器主要通过双向滚圆扩增（B-RCA）等核酸扩增技术激活 Cas12a 的反向裂解活性，进行信号转换，释放裂解发夹中的 Ag+，淬灭 QD 荧光，进行信号呈现。该生物传感器可进行荧光和比色检测，实现快速现场检测。它具有更强的选择性、更高的灵敏度和更高的准确性。最佳条件下的检测范围为 0.05 至 500 nM，最低检测浓度为 2.137 pM，超越了传统方法的性能。该生物传感器能有效检测实际环境样品中的 MC-LR。总之，这项研究为应用核酸检测技术检测环境中的痕量污染物提供了一种通用的检测方法。图文摘要

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引用次数: 0