Utilizing an Automated SERS-Digital Microfluidic System for High-Throughput Detection of Explosives

Abstract

The surface-enhanced Raman scattering (SERS) technique is a promising method for the detection of explosives such as 2,4,6trinitrotoluene (TNT) and 3-nitro-1,2,4-triazol-5-one (NTO) because of its high sensitivity to trace substances. However, most SERS detection processes are often nonautomated as well as exhibit low efficiency and toxic exposure, which often poses potential danger to operators. Herein, we propose the integration of SERS with digital microfluidics (SERS-DMF) for automated, high-throughput, and high-sensitivity detection of explosives. First, we carefully designed a DMF chip comprising 40 drive electrodes and 8 storage electrodes to achieve a high-throughput process. And different concentrations of target molecules, silver nanoparticles (Ag NPs), and salts were loaded into the DMF chip. Then, the droplet aggregation, incubation, and detection processes were automatically controlled using the SERS-DMF platform. In addition, Ag NPs were efficiently aggregated by screening different types and concentrations of salts, resulting in "hotspots" and the SERS effect. With the help of the SERS-DMF platform, two explosive samples were automatically detected with high throughput and high sensitivity. The detection limits of TNT and NTO were 10 −7 and 10 −8 M, respectively. In addition, compared with nonautomatic operations, the SERS-DMF platform exhibited better reproducibility and higher efficiency for the detection of explosives. The proposed SERS-DMF thus has considerable potential as an analytical technique for detecting hazardous substances.

Microfluidics for disease diagnostics based on surface-enhanced raman scattering detection

“…Liu et al developed a SERS-based DMF chip for the automated and highly sensitive detection of explosives in a high-throughput manner (Fig. 9 ) [ 58 ]. A DMF chip with 40 drives and eight storage electrodes was fabricated to implement a high-throughput process.…”

“…b The operational principle of the SERS-DMF platform emphasizes its capability for detecting high-throughput explosives. Reprinted with permission from [ 58 ]. Copyright 2023 American Chemical Society …”

On-Chip Photonic Detection Techniques for Non-Invasive In Situ Characterizations at the Microfluidic Scale

“…Importantly, SERS eliminates any interference from water and does not cause damage to samples, making it suitable for the analysis of biological samples [ 81 , 82 , 83 , 84 , 85 , 86 ] or cancer diagnostics [ 87 , 88 , 89 , 90 , 91 ]. Equally, microfluidic sensors based on SERS detection have been proposed for very diverse applications, ranging from the diagnosis of Alzheimer’s disease [ 92 ] to the rapid analysis of food contaminants [ 93 ] or the high-throughput detection of explosives [ 94 ] or harmful substances [ 95 ]. Li and co-workers developed a novel microfluidic SERS sensor integrated with a side-polished multimode fiber (SPMF).…”

Highly sensitive fluorescent explosives detection via SERS: based on fluorescence quenching of graphene oxide@Ag composite aerogels

“…Owing to the crucial requirement for homeland security, detecting trace explosives with high precision has recently garnered accelerated attention. 1–3 The generation, carriage and employment of explosives unavoidably result in soil and groundwater contamination. 4,5 Furthermore, explosive remnants can lead to severe ailments like cataracts, anaemia, and cancer.…”