A concentration-dependent multicolor conversion strategy for ultrasensitive colorimetric immunoassay with the naked eye.
Colorimetric immunoassays have been attracting more attention for use in practical applications, especially in point-of-care diagnostics. In comparison with a single color immunoassay, the dose-dependent multicolor strategy greatly improves the detection resolution and accuracy of visual inspection. In the current study, a concentration-dependent multicolor conversion strategy was developed based on gold nanoparticle (AuNP)-mediated copper deposition for signal amplification and Prussian blue for color generation. Under optimal conditions, a dose-dependent multicolor from yellow through green to blue were successfully achieved, which was easier to be differentiated from each other by the naked eyes. With rabbit IgG and prostate specific antigen (PSA) as model analytes, semi-quantitative evaluations were demonstrated in lab buffer and serum by direct readout with the naked eyes. Quantitative detections were also accomplished by measurement of absorbance of Prussian blue with a common UV-Vis spectrophotometer. A limit of detection (LOD) down to sub-picogram per milliliter was determined. In addition, this newly developed colorimetric assay method can be easily adapted for the detection of other biomolecules by simply changing the recognition pairs.
Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, China; Chongqing Engineering Research Center for Rapid Diagnosis of Dread Disease, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing, 400715, China. Electronic address: ysliu@swu.edu.cn.
Yingshuai
Y
Liu
Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, China; Chongqing Engineering Research Center for Rapid Diagnosis of Dread Disease, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing, 400715, China.
Zeying
Z
Zhang
Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, China; Chongqing Engineering Research Center for Rapid Diagnosis of Dread Disease, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing, 400715, China.
Jie
J
Yu
Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, China; Chongqing Engineering Research Center for Rapid Diagnosis of Dread Disease, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing, 400715, China.
Jin
J
Xie
Institute for Clean Energy & Advanced Materials, Faculty of Materials & Energy, Southwest University, Chongqing, 400715, China; Chongqing Engineering Research Center for Rapid Diagnosis of Dread Disease, Southwest University, Chongqing, 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing, 400715, China.
Chang Ming
CM
Li
D000818:Animals; D003116:Color; D003124:Colorimetry / Q000379:methods*; D003300:Copper / Q000737:chemistry; D005295:Ferrocyanides / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis; D007501:Iron / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry
D005295:Ferrocyanides; D007074:Immunoglobulin G; D006046:Gold; D003300:Copper; D007501:Iron; C000170:ferric ferrocyanide
Cancer diagnosis; Colorimetric immunoassay; Copper deposition; Gold nanoparticle (AuNP); Multicolor conversion; Signal amplification