Application of Plasma-Printed Paper-Based SERS Substrate for Cocaine Detection

Abstract

Surface-enhanced Raman spectroscopy (SERS) technology is an attractive method for the prompt and accurate on-site screening of illicit drugs. As portable Raman systems are available for on-site screening, the readiness of SERS technology for sensing applications is predominantly dependent on the accuracy, stability and cost-effectiveness of the SERS strip. An atmospheric-pressure plasma-assisted chemical deposition process that can deposit an even distribution of nanogold particles in a one-step process has been developed. The process was used to print a nanogold film on a paper-based substrate using a HAuCl4 solution precursor. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the gold has been fully reduced and that subsequent plasma post-treatment decreases the carbon content of the film. Results for cocaine detection using this substrate were compared with two commercial SERS substrates, one based on nanogold on paper and the currently available best commercial SERS substrate based on an Ag pillar structure. A larger number of bands associated with cocaine was detected using the plasma-printed substrate than the commercial substrates across a range of cocaine concentrations from 1 to 5000 ng/mL. A detection limit as low as 1 ng/mL cocaine with high spatial uniformity was demonstrated with the plasma-printed substrate. It is shown that the plasma-printed substrate can be produced at a much lower cost than the price of the commercial substrate.

Applications of surface‐enhanced Raman spectroscopy based on portable Raman spectrometers: A review of recent developments

“…However, with the continuous increase in the variety and dosage of drugs, the irregularity of drug production and excessive drug use have posed a serious threat to human health. [ 123,124 ] The development of drug testing technology plays an important role in improving drug safety and improving quality of life. In recent years, the development of sensitivity, stability, real‐time, and trace detection of drug detection has attracted more and more researchers' interest.…”

“…However, with the continuous increase in the variety and dosage of drugs, the irregularity of drug production and excessive drug use have posed a serious threat to human health. [123,124] The development of drug testing technology plays an important role in improving drug safety and improving quality of life.…”

Interpol Review of Drug Analysis 2019-2022

“…2019 DART-HRMS method to detect organic impurities in cocaine samples seized in China [ 29 ]; electrochemical sensor for direct detection of cocaine [ 30 ]; analysis of the role of TiO2 nanoparticles and UV irradiation in the enhancement of SERS spectra to improve levamisole and cocaine detection [ 31 ]; aptamer-based liquid crystal sensor for detection of cocaine [ 32 ]; 2020 High-throughput screening of cocaine, adulterants, and diluents in seized samples using capillary electrophoresis with capacitively coupled contactless conductivity for detection and simultaneous quantification of cocaine, levamisole, lidocaine, carbonate, borate, chloride, nitrate, nitrite and sulfate [ 33 ]; a method using carbon paste chemically modified with N,N′-ethylene-bis-(salicylideneiminato) manganese(II) to detect cocaine hydrochloride by linear sweep voltammetry (LSV) in aqueous medium [ 34 ]; synthesis of an optical sensor for use in the detection/quantification of lidocaine in seized cocaine hydrochloride samples [ 35 ]; development of a sensor based on molecularly imprinted polymer nanoparticles (nanoMIPs) and electrochemical impedance spectroscopy (EIS) for the detection of trace levels of cocaine [ 36 ]; chemosensor for detection of cocaine [ 37 ]; comparison study of the performance of three spectroscopic techniques [MIR, Raman and NIR] on a total of 364 seized powders - 276 cocaine powders (with concentrations ranging from 4 to 99 w%) and 88 powders without cocaine [ 38 ]; sensor for detection of cocaine [ [39] , [40] , [41] ]; sensor for detection of cocaine by-products [ 42 ]; novel application of 740–1070 nm small-wavelength-range NIR spectroscopy and machine learning algorithms for on-site detection of cocaine in illicit substances [ 43 ]; nanosensor for cocaine detection [ 44 ]; Surface-enhanced Raman Scattering (SERS) method for detection of cocaine on banknotes [ 45 ]; Ion Mobility Spectrometry (IMS) and LC-MS/MS for detection of cocaine on banknotes [ 46 ]; portable handheld Raman spectrometer for detection of cocaine [ 47 ]; colorimetric sensor for cocaine [ 48 , 49 ]; fluorescence sensor for cocaine [ 50 ]; 2021 plasma-printed paper-based SERS substrate for detection of Cocaine at concentrations from 1 to 5000 ng/mL [ 51 ]; comparison of seven commercial SERS substrates A-G for the analysis of cocaine [ 52 ]; a multiple detection paper-based analytical device that combines colorimetric and electrochemical measurements for determining the composition of seized cocaine samples in order to isolate adulterant content [ 53 ]; ICP-MS and Inductively coupled plasma - optical emission spectrometry (ICP-OES) analysis of inorganic profiles of seized Coca...…”

Recent Advances in the Use of Surface-Enhanced Raman Scattering for Illicit Drug Detection

“…The most commonly used SERS substrates are colloid-based due to their high stability, low cost, and ease of fabrication and implementation. Owing to the advances in nanotechnology and nanoscience, metallic nanoparticles with different shapes and sizes have been synthesized through chemical replacement [ 37 ], chemical reduction [ 38 ], thermal deposition [ 39 , 40 ], chemical deposition [ 41 ] and ultrasonic decomposition methods [ 42 ]. Due to their high surface plasmon resonance effect in the visible and the near-infrared wavelength ranges, colloidal silver and gold with sizes ranging from 10–150 nm are the most common metallic particles used for SERS-active substrates [ 29 ].…”