X (Metal: Al, Cu, Sn, Ti) - functionalized tunable 2D-MoS2 nanostructures assembled biosensor array for qualitative and quantitative analysis of vital neurological drugs
In this work we report for the first time surface functionalization of 2D MoS2 with X (Metal : Al, Cu, Sn, Ti) to develop a low-cost, ultra-selective biosensor array based Electronic Tongue (E-Tongue) for detection of 4 vital neurological drugs in human saliva. The hydrothermally grown surface functionalized X-MoS2 were integrated onto a single 1 x 1 cm aluminium foil and contacts were defined using Cr electrodes. Detailed characterization revealed the formation of 2-H MoS2 and metal-X (Al, Cu, Sn, Ti) - functionalized MoS2 nanoflowers like morphology decorated with nanoflakes, nanorods, nanocubes and nanosticks structures respectively. The response of the sensor array was recorded for Aspirin, Nicotine, Caffeine and Tramadol. Principal Component Analysis (PCA) was employed to reduce the dimension of numerous response data set from all sensors and predicts the likely possible response from various neurological drugs towards each sensor. The pattern-recognition analysis confirmed a definite pattern in response for respective functionalization and could efficiently differentiate neurological drugs from one another. Real-time analysis was done using saliva samples for monitoring the therapeutic neurological drug concentration in human body. Further the biosensor array was exposed with respective neurological drugs to study the sensitivity, selectivity, stability, reproducibility and adhesion on the of the device. The strategy outlined can be used to develop lab-on-a-chip devices for real-time detection of numerous bio analytes in body fluids.