Silicon nanowires/reduced graphene oxide nanocomposite based novel sensor platform for detection of cyclohexane and formaldehyde

The present work provides a new reduced graphene oxide (rGO) modified silicon nanowires (SiNW) nanocomposite-based platform for the fabrication of a sensor. The fabricated sensor was used for the detection of biomarkers of infectious diseases in an easy, inexpensive, and non-invasive way. SiNW have been synthesized using metal-assisted chemical etching technique (MACE) and were casted using GO at room temperature. Subsequently, SiNW/GO was reduced to SiNW/rGO nanocomposite under an inert atmosphere using argon gas and characterized using a scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometer (EDS), fourier transform infrared (FTIR), X-ray diffractometer (XRD) and Raman spectroscopy. This film was fabricated in the form of an electrode and utilized for the sensitive and selective detection of two volatile organic compounds (VOCs) namely cyclohexane and formaldehyde, found in the exhaled breath of patients with certain infections. The SiNW/rGO nanocomposite sensor showed a contrary response of 1.07 and 0.99 for 1 ppm concentration of cyclohexane and formaldehyde, respectively at room temperature. It showed a limit of detection (LOD) of 1 ppm and exhibits a fast response time of 30 s at ambient conditions. The recovery time of the sensor was 1-2 min and 3 min for cyclohexane and formaldehyde, respectively. Thus, the reported sensing approach using SiNW/rGO nanocomposite could exhibit a new nanocomposite for the fabrication of sensors having high sensitivity, selectivity, repeatability, and stability for target analytes.

Automated summary

The study presents a method for fabricating sensors using silicon nanowires/reduced graphene oxide nanocomposite to detect volatile organic compounds in exhaled breath with high sensitivity and rapid response time.