(In collaboration with Profs. Ivan Mijakovic, Nina Kann (Chalmers), C. Hannoun (Sahlgrenska), and Perpetuus Carbon Technologies Ltd (UK))
The project aims at developing cost-effective graphene-based biosensors, addressing several top-priority societal problems related to health care. There is a growing market for such sensors: according to P&S Market Research, the global biosensors market was valued at $13 billion in 2014, and is expected to grow to $22.5 billion by 2020. The increased demand of biosensors is mostly due to the growing aging population, increasing health awareness, and rising chronic diseases.
The main challenge is to develop highly specific sensors that can detect particular metabolites or bacteria in a complex mixture. The important objective is to work out principles of how to preserve originally high sensitivity of graphene to analytes even after graphene functionalization. We believe that some non-covalently bonded sensor molecules should be used for the task. A simple electronics accommodating fast readout of multiple sensors will be appropriate for detection of several target analytes in one measurement sweep.
Figure. (a) Typical change of graphene resistance due to adsorbates and the gate voltage Vg. µ = 1000 cm2/(V s); n0 = 4e12 cm-2 (solid curves); Vg scale is for 275 nm thick SiO2 as gate insulator . The resistance change δR at Vg = 0 is larger for n0 = 1e12 cm-2 (dashed lines). (b) Intended sensor layout with six graphene elements. (c) A prototype sensor with two graphene elements allowing four-probe measurements, to eliminate the contact resistance Rcont. The metal thin films and contacts on the chip are covered by a biocompatible polymer (PDMS).