Sensitive detection of thyroid stimulating hormone by inkjet printed microchip with a double signal amplification strategy

摘要

An electrochemical immunosensor for sensitive detection of thyroid stimulating hormone(TSH) has been developed by using an inkjet printed microchip and based on a double signal amplification strategy using magnetic beads(MBs), alkaline phosphatase(ALP) and p-aminophenyl phosphate(pAPP) reaction.Differential pulse voltammetry(DPV), cyclic voltammogram(CV) and amperometric i-t curve(i-t) were employed to characterize the immunosensor. High sensitivity and good selectivity were observed. The detection linear range was from 0.01 μIU/mL to 10 μIU/mL, in which the peak currents increased along with the concentration. The detection limit was 0.005 μIU/mL at S/N = 3. The immunosensor was also applied for TSH detection in human serum with recoveries from 98.0% to 101.8% and relative standard deviations from 1.3% to 3.1%, demonstrating potential value in clinical diagnosis.