Wafer-scale nanocracks enable single-molecule detection and on-site analysis
Journal
Biosensors and Bioelectronics
Journal Volume
200
Date Issued
2022
Author(s)
Abstract
Large-area surface-enhanced Raman spectroscopy (SERS) sensing platforms displaying ultrahigh sensitivity and signal uniformity have potentially enormous sensing applicability, but they are still challenging to prepare in a scalable manner. In this study, silver nanopaste (AgNPA) was employed to prepare a wafer-scale, ultrasensitive SERS substrate. The self-generated, high-density Ag nanocracks (NCKs) with small gaps could be created on Si wafers via a spin-coating process, and provided extremely abundant hotspots for SERS analyses with ultrahigh sensitivity—down to the level of single molecules (enhancement factor: ca. 1010; detection limit: ca. 10–18 M)—and great signal reproducibility (variation: ca. 3.6%). Moreover, the Ag NCK arrays demonstrated broad applicability and practicability for on-site detection when combined with a portable 785 Raman spectrometer. This method allowed the highly sensitive detection of a diverse range of analytes (benzo[a]pyrene, di-2-ethylhexyl phthalate, aflatoxins B1, zearalenone, ractopamine, salbutamol, sildenafil, thiram, dimethoate, and methamidophos). In particular, pesticides are used extensively in agricultural production. Unfortunately, they can affect the environment and human health as a result of acute toxicity. Therefore, the simultaneous label-free detection of three different pesticides was demonstrated. Finally, the SERS substrates are fabricated through a simple, efficient, and scalable process that offers new opportunities for mass production. ? 2021 Elsevier B.V.
Subjects
Nanocracks
On-site detection
Portable Raman spectrometer
Silver nanopaste
Single-molecule detection
Surface-enhanced Raman spectroscopy
Agriculture
Light transmission
Molecules
Raman spectroscopy
Sensitivity analysis
Silicon wafers
Silver
Spectrometers
Substrates
Nano-cracks
On-site analysis
Portable raman spectrometer
Raman spectrometers
Surface enhanced Raman spectroscopy
Ultra-high-sensitivity
Wafer scale
Pesticides
metal nanoparticle
silver
thiram
genetic procedures
human
Raman spectrometry
reproducibility
Biosensing Techniques
Humans
Metal Nanoparticles
Reproducibility of Results
Spectrum Analysis, Raman
Thiram
Type
journal article