ACS Measurement Science Au最新文献

[This corrects the article DOI: 10.1021/acsmeasuresciau.3c00026.].

Colorectal cancer (CRC) is one of the most treatable cancers, yet it ranks second in mortality worldwide. Early detection significantly impacts treatment outcomes, but early stage CRC often presents no symptoms or nonspecific symptoms. The current screening methods are invasive and lacks specificity, hindering widespread CRC screening efforts. This underscores the urgent need for improved CRC screening tools. In this study, a label-free impedimetric immunosensor for detecting colon cancer-secreted protein-2 (CCSP-2), which exhibits a mean 78-fold increase in primary colon cancers compared to normal mucosa, was developed. Our cost-effective and noninvasive electrochemical immunosensor for CCSP-2 biomarker detection aims to facilitate early diagnosis and monitoring of CRC. The designed immunosensor features a functionalized gold electrode (Au) modified with cysteine-modified recombinant protein G (RPGCys) to immobilize the CCSP-2 antibody (Ab), and bovine serum albumin (BSA) used to prevent sensor surface fouling. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to analyze the electrochemical response to the binding of CCSP-2 antigen (Ag) and Ab. The changes in relative charge transfer resistance (ΔR_ct/R_cti) with varying concentrations of Ag were plotted and a calibration curve was established between ΔR_ct/R_cti and logarithm of Ag concentration to assess sensor’s sensitivity. The sensor demonstrated a linear response (R² = 0.95) within the range of 10–100 ng/μL, plateauing after 100 ng/μL, with a detection limit of 0.71 ng/μL. Statistical analysis of specificity and selectivity studies showed significant differences in Ag detection compared to blank and nonspecific protein BSA, both with and without cell extracts. This immunosensor effectively detects the CRC biomarker CCSP-2 with high sensitivity and specificity. Integrating this sensor with other sensors for serum CRC biomarkers present a promising approach for developing diagnostic and prognostic tools for CRC.

Colorectal cancer (CRC) is one of the most treatable cancers, yet it ranks second in mortality worldwide. Early detection significantly impacts treatment outcomes, but early stage CRC often presents no symptoms or nonspecific symptoms. The current screening methods are invasive and lacks specificity, hindering widespread CRC screening efforts. This underscores the urgent need for improved CRC screening tools. In this study, a label-free impedimetric immunosensor for detecting colon cancer-secreted protein-2 (CCSP-2), which exhibits a mean 78-fold increase in primary colon cancers compared to normal mucosa, was developed. Our cost-effective and noninvasive electrochemical immunosensor for CCSP-2 biomarker detection aims to facilitate early diagnosis and monitoring of CRC. The designed immunosensor features a functionalized gold electrode (Au) modified with cysteine-modified recombinant protein G (RPGCys) to immobilize the CCSP-2 antibody (Ab), and bovine serum albumin (BSA) used to prevent sensor surface fouling. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to analyze the electrochemical response to the binding of CCSP-2 antigen (Ag) and Ab. The changes in relative charge transfer resistance (ΔR _ct/R _cti) with varying concentrations of Ag were plotted and a calibration curve was established between ΔR _ct/R _cti and logarithm of Ag concentration to assess sensor's sensitivity. The sensor demonstrated a linear response (R ² = 0.95) within the range of 10-100 ng/μL, plateauing after 100 ng/μL, with a detection limit of 0.71 ng/μL. Statistical analysis of specificity and selectivity studies showed significant differences in Ag detection compared to blank and nonspecific protein BSA, both with and without cell extracts. This immunosensor effectively detects the CRC biomarker CCSP-2 with high sensitivity and specificity. Integrating this sensor with other sensors for serum CRC biomarkers present a promising approach for developing diagnostic and prognostic tools for CRC.

[This corrects the article DOI: 10.1021/acsmeasuresciau.2c00070.].

Compared with the conventional analytical methods, nanozyme-based colorimetric sensors offer simpler and more accessible solutions for point-of-need food safety monitoring. Herein, Alginate-Cu (AlgCu) is reported as a robust laccase mimetic nanozyme for the colorimetric detection of sulfite in red wine, a common preservative in winemaking. AlgCu represents a rational design of nanozymes where the multifunctional group alginate is used as a coordination environment for the Cu catalytic center, mimicking the amino acids microenvironment in the natural laccase. The laccase activity of the AlgCu is evaluated using 2,4-dichlorophenol as a model substrate, where its oxidized product reacts with 4-aminoantipyrine, forming a reddish-pink compound with an absorption peak at 510 nm. The result showed that the AlgCu exhibited 32.81% higher laccase activity than pristine copper NPs, highlighting the role of a coordination environment in improving catalytic activity. The addition of sulfite decreased the intensity of the catalytic chromogenic product, confirming that sulfite inhibited the laccase mimetic activity of AlgCu. The observed inhibition is linearly related to the sulfite concentration from 2 to 100 μM (R² = 0.996), enabling the detection of sulfite down to 0.78 μM. Furthermore, a sulfite concentration down to 4.9 μM could be detected by integrating the colorimetric assay with smartphone color readouts. Analysis of sulfite-spiked red wine samples gave recoveries between 96 and 106%. Overall, the obtained analytical figures of merits signify AlgCu as a robust nanozyme-based colorimetric chemosensor suitable for a point-of-need application in wine quality control and food safety monitoring in general.

Compared with the conventional analytical methods, nanozyme-based colorimetric sensors offer simpler and more accessible solutions for point-of-need food safety monitoring. Herein, Alginate-Cu (AlgCu) is reported as a robust laccase mimetic nanozyme for the colorimetric detection of sulfite in red wine, a common preservative in winemaking. AlgCu represents a rational design of nanozymes where the multifunctional group alginate is used as a coordination environment for the Cu catalytic center, mimicking the amino acids microenvironment in the natural laccase. The laccase activity of the AlgCu is evaluated using 2,4-dichlorophenol as a model substrate, where its oxidized product reacts with 4-aminoantipyrine, forming a reddish-pink compound with an absorption peak at 510 nm. The result showed that the AlgCu exhibited 32.81% higher laccase activity than pristine copper NPs, highlighting the role of a coordination environment in improving catalytic activity. The addition of sulfite decreased the intensity of the catalytic chromogenic product, confirming that sulfite inhibited the laccase mimetic activity of AlgCu. The observed inhibition is linearly related to the sulfite concentration from 2 to 100 μM (R ² = 0.996), enabling the detection of sulfite down to 0.78 μM. Furthermore, a sulfite concentration down to 4.9 μM could be detected by integrating the colorimetric assay with smartphone color readouts. Analysis of sulfite-spiked red wine samples gave recoveries between 96 and 106%. Overall, the obtained analytical figures of merits signify AlgCu as a robust nanozyme-based colorimetric chemosensor suitable for a point-of-need application in wine quality control and food safety monitoring in general.