Electrochemical paper-based microfluidic device for on-line isolation of proteins and direct detection of lead in urine

In this work, we developed a microfluidic paper-based analytical device (mu PAD) for the on-line isolation of proteins and the electrochemical detection of lead ions (Pb(II)) in urine samples. The patterned filter paper was prepared through the direct printing of microchannel patterns on filter paper using an office laser printer. The paper was modified with protein precipitant and was then coupled with a detachable three-electrode system. Experimental parameters, namely, modification reagents, microchannel length and width, deposition potential, and deposition time, were optimized. Then, the maximum protein concentration under which the device can function was obtained as 300 mg L-1. The linear range was 10-500 mu g L-1 with a detection limit of 9 mu g L-1. The effectiveness of this device was demonstrated through the quantification of Pb(II) in urine samples and the results agreed with those of atomic absorption spectrometry (AAS).

Automated summary

In this study, a microfluidic paper-based analytical device (muPAD) was developed for the online isolation of proteins and electrochemical detection of lead ions (Pb(II)) in urine samples. Experimental parameters were optimized, leading to a maximum protein concentration of 300 mg L-1, a linear range of 10-500 µg L-1, and a detection limit of 9 µg L-1. The device's effectiveness was demonstrated through quantification of Pb(II) in urine samples, showing results consistent with atomic absorption spectrometry (AAS).