Label-free low-cost disposable DNA hybridization detection systems using organic TFTs

Organic thin film transistors (OTFT) are potentially very attractive for making portable and disposable DNA hybridization detection toolkits because of their ultra-low-cost manufacturing and potentially high sensitivity. To make a self-supported DNA sensor, we herein report an OTFT-based label-free DNA hybridization detection system integrating electrically read DNA hybridization sensors and microfluidic delivery channels. We previously reported DNA-doped OTFTs acting as electrically read DNA sensors. In this article, we first study physics of DNA sensitivity of OTFTs, clarifying the doping mechanism. The article also presents a method of verification of the immobilization and presence of DNA on the surface using TOF-SIMS analysis. As a further step, sources of variation of measured data and methods of minimization are discussed using a novel photolithography-based microfluidics fabrication method, directly enabling on-chip hybridization and self-supported DNA detection. By integrating the sensors with microfluidics, for the first time, we demonstrate necessary technologies required to realize disposable, rapid turn-around tools for field-deployable genetic diagnosis.