Investigating the potential of ZTO as an efficient and cheap SERS substrate for the identification of bacteria

A Zohaib,A Mateen,K Mahmood,A Ali,N Amin

doi:10.1063/5.0046002

Abstract

In recent years, Surface Enhanced Raman Spectroscopy (SERS) has been considered the best tool for the detection and identification of the least concentration of analytes and micro-organisms, such as bacteria. In this article, we have successfully obtained the SERS signal of Escherichia coli and Methylene Blue (MB) using Zinc Tin Oxide (ZTO) nanostructures as the SERS substrate. The ZTO SERS substrates were grown by a simple thermal evaporation method and annealed at various temperatures ranging from 600 to 800 °C before using them for bacteria identification. After the structural verification and morphological analysis using XRD and SEM, ZTO samples were used as SERS substrates for the detection of E. coli and MB by placing a drop of each solution on the ZTO. SERS data strongly identified the presence of MB and E. coli Raman peaks. Furthermore, it was found that intensity of signals (for both E. coli and MB) was found to be improved from SERS substrates that are pre-annealed at higher temperature. The intensity of Raman peaks for E. coli and MB was increased by 60 000 and 120 000 counts as the annealing temperature increased to 600 and 800 °C, respectively. An enhancement factor of 1.44 × 104 was observed for MB. Results obtained in this study indicate that zinc oxide based nanostructured SERS chips are potential candidates for rapid identification of many pathogens.

Highlights

In recent years, Surface Enhanced Raman Spectroscopy (SERS) has emerged as a potential detection tool in many industrial fields, such as nutrition safety, atmosphere monitors, biosensors, and catalysis chemistry, due to its non-destructive and highly sensitive diagnostic capability.1–5 it has several advantages, such as being inexpensive, reliable, and fast; it can detect single molecules; and it has a high signal to noise ratio when compared to conventional and time consuming diagnostic techniques.6 the detection signal of any pathogen is supposed to be very weak and needs to be enhanced for the powerful detection of bacteria
The samples were subjected to the annealing process at different temperatures ranging from 600 to 800 ○C with a step of 100 ○C for 1 h. These Zinc Tin Oxide (ZTO) samples were used as the SERS substrate for the detection of Methylene Blue (MB) and E. coli
A very inexpensive and efficient SERS substrate based on ZTO nanostructures was fabricated using the thermal evaporation method

Summary

INTRODUCTION

Surface Enhanced Raman Spectroscopy (SERS) has emerged as a potential detection tool in many industrial fields, such as nutrition safety, atmosphere monitors, biosensors, and catalysis chemistry, due to its non-destructive and highly sensitive diagnostic capability. it has several advantages, such as being inexpensive, reliable, and fast; it can detect single molecules; and it has a high signal to noise ratio when compared to conventional and time consuming diagnostic techniques. the detection signal of any pathogen is supposed to be very weak and needs to be enhanced for the powerful detection of bacteria. Surface Enhanced Raman Spectroscopy (SERS) has emerged as a potential detection tool in many industrial fields, such as nutrition safety, atmosphere monitors, biosensors, and catalysis chemistry, due to its non-destructive and highly sensitive diagnostic capability.. Surface Enhanced Raman Spectroscopy (SERS) has emerged as a potential detection tool in many industrial fields, such as nutrition safety, atmosphere monitors, biosensors, and catalysis chemistry, due to its non-destructive and highly sensitive diagnostic capability.1–5 It has several advantages, such as being inexpensive, reliable, and fast; it can detect single molecules; and it has a high signal to noise ratio when compared to conventional and time consuming diagnostic techniques.. It is reported that the EM enhancement factor strongly depends on the morphological and structural properties of the substrate material. The observed results are explained in detail with the help of available literature

EXPERIMENTAL SECTION

AND DISCUSSION

CONCLUSION