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Dendritic core-shell rhodium@platinum-cobalt nanocrystals for ultrasensitive electrochemical immunoassay of squamous cell carcinoma antigen

Chen, Yao, Feng, Jiu-Ju, Mei, Li-Ping, Shi, Chuan-Guo, Wang, Ai-Jun
Journal of colloid and interface science 2019 v.555 pp. 647-654
antigens, biomarkers, blood serum, catalytic activity, catechol, detection limit, disease surveillance, electrochemistry, immunoassays, immunosensors, nanocrystals, oxidation, rhodium, squamous cell carcinoma
Squamous cell carcinoma antigen (SCCA) has great diagnostic values for its high specificity (90–96%) in diagnosis of squamous cell carcinoma especially cancers, where electrochemical immunoassay is powerful for its accurate and reliable detection of specific tumor biomarkers at very low levels. In this work, well-defined three-dimensional dendritic core-shell rhodium@platinum-cobalt nanocrystals (Rh@PtCo NCs) were facilely prepared via a simple one-pot solvothermal strategy. Taking advantage of dramatically enhanced catalytic activity of the Rh@PtCo NCs for catechol oxidation, a label-free electrochemical immunosensor was developed for highly sensitive assay of SCCA. Under optimal conditions, the electrochemical signals were linearly correlated with the logarithm of the SCCA concentration, showing a broad linear range from 0.0001 to 10.0 ng mL−1 and a ultralow detection limit of 0.04 pg mL−1 (S/N = 3). The resultant immunosensor was further exploited for actual analysis of serum samples with convinced results. This immunosensor has good expectation in actual samples analysis and provides a universal approach for detection of other tumor markers and disease surveillance.