Determination of Microcystin in Water Using Electrochemical Method Based on Quantum Dot/Antibody Probe

Abstract:

With the probe of quantum dots coupled with microcystin antibody（QDs-Ab），the content of microcystin was determined by measuring cadmium ions released from QDs based on square wave stripping voltammetry after indirect competitive reaction. The electrochemical response was optimized with respect to pH，buffer concentration，deposition potential，deposition time and so on. Results showed that the sensitive stripping peak potential of cadmium ions was about -0.768 V. Under the optimal conditions，the peak current was linear with the logarithm of microcystin concentration in the range of 0.1~8 μg/L and the equation of regression was y=-196.66x+242.15（R2=0.994 8） with a detection limit of 0.08×10-9. The recovery of standard addition experiment was in the range of 91%~108.6% with the relative standard deviation of 2.97%~6.98%.