Ultrasensitive immunoassay of breast cancer type 1 susceptibility protein (BRCA1) using poly (dopamine-beta cyclodextrine-Cetyl trimethylammonium bromide) doped with silver nanoparticles: A new platform in early stage diagnosis of breast cancer and efficient management

Abstract Breast cancer type 1 susceptibility protein (BRCA1) is antioncogenes in women, who are genetically predisposed to breast cancer. Therefore, development of a reliable method for sensitive and selective detection of BRCA1 with low concentration level is very important. In this research work a novel immunoassay based on signal amplification strategy of multiple polymers to recognition of BRCA1 protein was developed. The engineered immunoassay prepared by poly (dopamine-beta cyclodextrine-Cetyl trimethylammonium bromide doped by silver nanoparticles (P[DA- β -CD/CTAB])-AgNPs) and functionalized mesoporous silica (MCM-41-SO 3 H) composite fabricated on the glassy carbon electrode with a large surface area which was prepared a new platform to immobilization of primary antibodies and provide excellent conductivity. To further amplify the electrochemical signal, MCM-41-SO 3 H provides suitable pores volume and functional groups to capture more horseradish peroxidase-labeled antibodies (HPR-Ab2) and enhances the conductivity. The proposed immunoassay displays suitable analytical performance for the monitoring of BRCA1 with a linear range from 0.01565–10 pg/mL (by DPV) and 0.625–20 pg/mL (by SWV) and a low limit of quantification of 0.003 pg/mL. Also, satisfactory results are obtained for the determination of BRCA1 in human plasma samples and MCF-7 cancer cell lysates, indicating the potential of the immunoassay to be applied in clinical analysis.