Surface-Enhanced Raman Scattering Detection Based on an Interconnected Network of Vertically Oriented Semiconducting Few-Layer MoS<sub>2</sub> Nanosheets
Bishnu Pada Majee, Vishal Srivastava, Ashish Kumar Mishra
Abstract
As an alternative to costly metals (Au and Ag), semiconducting metal dichalcogenide nanostructures can be used as active surface-enhanced Raman spectroscopy (SERS) substrates for the detection of organic pollutants; however, they suffer from lower detection efficiency. In the present work, we analyze the semiconducting behavior of chemical-vapor-deposition-grown interconnected and vertically oriented few-layer MoS2 nanosheets by a temperature-dependent photoluminescence study. The prepared semiconducting pristine MoS2 nanosheets over Si show the ultrasensitive SERS detection of organic dyes, Rhodamine 6G, and Methyl Orange at subnanomolar (10–10 M) concentrations, which is the highest detection limit for pristine MoS2 nanostructures as SERS substrates to the best of our knowledge. The high detection limit of interconnected and vertically oriented few-layer MoS2 nanosheets as SERS substrates is attributed to the enhanced light trapping and effective adsorption of dyes due to the morphology of prepared MoS2 SERS substrates along with vibronic-coupling-enabled charge transfer between MoS2 and organic dyes.