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Updated: May 14, 2026
Experimental Protocol for Detecting Cyanobacteria in Liquid and Solid Samples with an Antibody Microarray Chip
Published on: February 7, 2017
Nanozyme and bifunctional nanobody-based colorimetric-SERS dual-mode Immunosensor for microcystin-LR detection
Long Wu1, Luyao Jiao2, Danni Xue2
1School of Food Science and Engineering, Key Laboratory of Tropical Fruits and Vegetables Quality and Safety, State Administration for Market Regulation, Hainan University, Haikou 570228, PR China; State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, Liaoning, PR China.
Abstract:
Microcystin-LR (MC-LR), a potent cyanotoxin in freshwater, poses a risk of severe liver damage and other health issues, making its detection vital. However, the detection capabilities of conventional antibodies are constrained, which limited their use in immunoassays. In this work, we designed a new bifunctional nanobody, named A2.3-SBP (comprised of nanobody and streptavidin binding peptide), capable of binding with MC-LR and streptavidin. Based on A2.3-SBP and Fe3O4@Au-Pt nanozyme, we introduced an enzyme-free immunosensor that operated in microplate with colorimetric and surface-enhanced Raman scattering (SERS) detection modes. The dual-mode assay showed color changes and SERS intensity directly correlating to MC-LR concentrations with a range from 1.0 to 500 ng/mL and a limit of detection of 0.26 and 0.032 ng/mL, respectively. This strategy eliminated the need for complex enzymatic reactions and realized dual-signal detection of MC-LR in 96 water samples (0.03 μg/kg) within 30 min, suggesting its potential in drinking water detection.
