Determination of Microcystin in water ssing electrochemical method based on quantum dot/antibody probe

• 1、School of Food Science and Technology,Jiangnan University, Wuxi,Jiangsu,214122
• 2、State Key Laboratory of Food Science and Technology, Jiangnan University,Wuxi, Jiangsu 214122

Abstract：We used quantum dots coupling with microcystin antibody (QDs-Ab) as probe, and then we can detect the content of microcystin by measuring the cadmium ions released from QDs based on square wave stripping voltammetry after indirect competitive reaction. The electrochemical response was characterized with respect to pH，concentration of buffer，deposition potential, deposition time and so on. The results showed that a sensitive stripping peak potential of cadmium ions is about -0.768V. Under the optimal conditions, the peak current is linear with the logarithm of the concentration of microcystin, whose concentration was in the range of 0.05ppb~8ppb, the equation of linear regression was y=-200.08x+243(R2=0.9948) with the detection limit of 0.018ppb. This method was used to determine microcystin in real water samples, and the recoveries of standard addition experiments were in the range of 91%~108.6% , with the relative standard deviation of 2.97%~6.98%.

Keywords： Microcystin；Quantum dots；cadmium ions；square wave stripping voltammetry（SWSV）