A novel detection method of human serum albumin based on CuInZnS quantum dots-Co²⁺ sensing system

We developed a novel "turn off-on" sensor for human serum albumin (HSA) detection based on CuInZnS quantum dots (CIZS QDs). The photoluminescence (PL) of QDs can be "turned off" by Co(II) first. Because of the strong binding ability of HSA with Co²⁺, Co²⁺ can be removed from CIZS QDs with the addition of HSA. As a result, the PL of CIZS QDs probe can be "turned on" with an increased concentration of HSA over a wide range. The analyte HSA concentration had a proportional linear relationship with the recovered PL intensity of CIZS QDs. The detection limit for HSA was 4.5 × 10^-8 mol L^-1. The results indicated that the CIZS QDs- Co²⁺-BSA sensing system possessed higher sensitivity and better practicability for HSA detection.