Fabrication of MoS2 Biosensor By Chemical Exfoliation

Abstract

The marriage between nanotechnology and sports is here [1]. We see it in new materials for tennis racquets, to balls, and to goal line technology to name a few [2]. One area that has amazing potential are wearable biosensors to improve the health and stamina of world class athletes [3]. In soccer (football) for example, some of the best athletes in world run almost 10 km during a match so keeping track of their health is very important. These real time bio signals while playing can help to avoid injuries and help long term longevity. The wearables sensors should stick to the athletes’ body seamlessly and not affect their play or performance. This can be done with new nanomaterials and devices. In this work, we use a 2D material, 1.3 nm thick MoS2 nano-flakes, to fabricate a bio sensor that can detect changes in temperature.The chemically exfoliated MoS2 nano-flakes are drop casted on a lightly P doped Si substrate. 50 nm thick Au metallization layer is deposited on both the back of the substrate and top of MoS2. Followed by another metallization layer using a shadow mask to pattern the top contacts. Finally, silver paste is applied to the back contact before mounting it on a gold-coated steel disc. The sensor is then placed on a hot plate and connected to a probe station where the steel plate is grounded, while the top contact voltage is swept from -5 to 5 V. The IV characteristics are measured from 30 oC to 120 oC with 5 oC increments.The collected IV plots from the sensor shows better responsivity and higher current response compared to the control sample with no MoS2. We then tested the current flow as function of temperature to detect changes. This simple design with nanotechnology and 2D materials will be fabricated next on flexible substrates and made into wearable device. This is perfect for world class athletes to detect sudden changes in bio-temp and send real time bio-signals to health care professionals.Finally, the use of bio sensor for athletes will become mainstream soon, help athletes stay healthy and avoid injuries. The use nanotechnology, and nanomaterials will be the key enabler of this. The results here show that 2D materials, like MoS2 are promising for future low cost wearable biosensors. Bibliography [1] M. P. Sadaf Abbasi, S. Nizamuddin and N. M. Mubarak, "Chapter 25 - Functionalized nanomaterials for the aerospace, vehicle, and sports industries," Micro and Nano Technologies, pp. 795-825, 2020. [2] L. P. d. Costa, "Chapter 14 - Engineered nanomaterials in the sports industry,," In Micro and Nano Technologies, Handbook of Nanomaterials for Manufacturing Applications,, pp. 309-320,, 2020. [3] J. Kim, A. Campbell and B. e. a. de Ávila, "Wearable biosensors for healthcare monitoring," Nat Biotechnol, no. 37, p. 389–406, 2019. Figure 1