Real-time nucleic acid detection via field-effect transistor sensors based on graphite oxide decorated with trimetallic nanocluster of gold, silver, and platinum

Abstract

Field effect transistor (FET) based sensors are witnessing robust evolutions in the fabrication and characterization for the purpose of biomedical applications. In this article, a graphite oxide FET based sensor is designed, fabricated, and characterized for real-time detection of various concentrations of nucleic acid with a detection limit of 1.28 nM of DNA. This sensor consists of two gold electrodes connected through a channel of graphite oxide. Moreover, the sensor sensitivity is enhanced by decorating the graphite oxide channel with composite trimetallic nanoclusters that include gold, silver, and platinum. The developed sensor is investigated by both simulation and experiment. Both experimental and simulation agree where the current signal is higher for sensors decorated with trimetallic nanoclusters, which indicate higher sensitivity. Moreover, increasing the concentration of DNA results in an increment in the current signal thus the response is proportional to DNA concentration. The results indicate a promising sensor for real-time, reliable, and cost-effective DNA detection.