Enzyme Multilayers on Graphene-Based FETs for Biosensing Applications

BLIEM, CHRISTINA; ESTEBAN PICCININI; KNOLL, WOLFGANG; AZZARONI, OMAR

METHODS IN ENZYMOLOGY.

ELSEVIER ACADEMIC PRESS INC

Lugar: Burlington, MA, Estados Unidos; Año: 2018

0076-6879

Electrochemical sensors present a powerful tool for real-time measurement of a variety of analytes in clinical diagnostics and food technology. Point-of-care devices which can be used at patient?s bedside or for online monitoring of critical parameters are of great importance in clinical and pharmaceutical daily routine. In this work portable, low cost electrochemical sensors have been developed for a fast and reliable detection of the clinically relevant analyte urea. The intrinsic pH sensitivity of reduced graphene oxide (rGO) based field-effect transistors (FETs) was exploited to monitor the enzymatic hydrolysis of urea. The functionalization of the sensor platform using the layer-by-layer (LbL) technique results as especially advantageous for the immobilization of the bioreceptor, preserving the integrity of the enzyme as well as the rGO surface. The great selectivity of enzyme combined with highly sensitive rGO based FETs result in biosensors with a limit of detection (LOD) of less than 1 µM for urea and a broad linear range up to 1 mM. Quantification of Cu2+ with a LOD down to 10 nM was performed by taking advantage of the urease specific inhibition by heavy metals. This versatile biosensor offers great possibilities for further development of highly sensitive enzyme based FETs for real-time, label free detection of a broad range of analytes.