Regenerable bead-based microfluidic device with integrated thin-film photodiodes for real-time monitoring of DNA detection

Abstract

Recently, systems for rapid diagnosis of diseases and infections have motivated the development of new DNA detection platforms. However, these platforms have failed to reach the market mainly because of the potential risk of misdiagnosis. Thus, developing a system with an effective internal control, guaranteeing the veracity of the result, could help overcome this barrier. The possibility to regenerate the microfluidic biosensing system would allow the implementation of the aforementioned internal control and the system's reusability, resulting in cost reduction. Nanoporous microbead-based microfluidic systems coupled with on-chip signal transduction can potentially allow significant enhancement of sensitivity for biosensing applications. In this paper, we report a regenerable bead-based microfluidic device that employs integrated thin-film photodiodes for real-time monitoring of DNA molecular recognition. The molecular identification of target DNA and complementary DNA is accomplished, followed by regeneration of the chip using 0.3 M of NaOH and control with a non-complementary target DNA. The best condition for immobilization of probe DNA to allow regeneration of the device was studied, and limits of detection of 1.2 nM and 3.1 nM were obtained for target DNA in buffer and human plasma, respectively, detected by fluorescence assays. Moreover, a chemiluminescence strategy provided the highest sensitivity to detect target DNA with a limit of detection of 78.5 pM. High-sensitivity assay cycles could be performed without significant loss of probe DNA, demonstrating the potential for the system's reusability, portability, and reproducibility.