AuNP decorated aegle marmelos leaf as SERS substrate for trace detection of antibiotics and machine learning based classification Dipjyoti Sarma, Macduf R Marak, Indrani Chetia, Laxmikant S Badwaik, Pabitra Nath Physica Scripta, 2024 Surface-enhanced Raman spectroscopy (SERS) has emerged as a reliable molecular spectroscopic technique for trace detection of chemical and biological samples. Present study illustrates a new SERS platform which has been obtained through surface adsorption of gold nanoparticles (AuNP) on a microscopically roughened surface of aegle marmelos (AM) leaf. The micro-structured patterns of the AM leaves promote the generation of hotspot regions for the surface deposited AuNPs thus, aids in electromagnetic enhancement for the scattered Raman signals from the sample. For the proposed SERS platform, with rhodamine6G (R6G) as an analyte, the limit of detection (LoD) was found to be 0.88 nM. The applicability of the designed SERS was realized through detection and quantification of two commonly used antibiotics- Ceftriaxone (CEFTR) and Ceftiofur sodium (CEF-Na) residues from cow milk samples. Furthermore, a dimensionality reduction method known as principal component analysis (PCA) and an optimal machine learning-based model were built to categorize the analytes in the milk samples. The suggested machine learning model’s classification accuracy was found to be 94%.
Gold nanoparticle deposited nylon filter paper as a sensitive SERS platform for trace sensing of enrofloxacin in aqueous medium Dipjyoti Sarma, Macduf R Marak, Pabitra Nath 2023 IEEE Workshop on Recent Advances in Photonics Wrap 2023, 2023 Surface-enhanced Raman Spectroscopy is a molecular sensing method; in it the Raman bands are enhanced manifold upon recording the Raman bands near the vicinity of metal nanostructured surface. The current work reports the fabrication of a low-cost SERS substrate which has been prepared through deposition of gold nanoparticle (AuNP)s over a nylon filter paper (NFP). The AuNPs present in the pores of the filter paper generates electromagnetic hotspot regions which enhance the Raman signals of the analyte. The NFP SERS substrate was first tested with a non-fluorescent dye - 1,2 - bis(4- pyridyl) ethylene (BPE). After testing with the standard Raman probes, the applicability of the fabricated SERS platform is realised through trace detection of a commonly used antibiotic enrofloxacin (ENX).
Gold nanoparticle decorated blu-ray digital versatile disc as a highly reproducible surface-enhanced Raman scattering substrate for detection and analysis of rotavirus RNA in laboratory environment Sritam Biswas, Yengkhom Damayanti Devi, Dipjyoti Sarma, Nima D. Namsa, Pabitra Nath Journal of Biophotonics, 2022 Detection and estimation of various biomolecular samples are often required in research and clinical laboratory applications. Present work demonstrates the functioning of a surface‐enhanced Raman scattering (SERS) substrate that has been obtained by drop‐casting of citrate‐reduced gold nanoparticles (AuNPs) of average dimension of 23 nm on a bare blu‐ray digital versatile disc (BR‐DVD) substrate. The performance of the proposed SERS substrate has been initially evaluated with standard Raman active samples, namely malachite green (MG) and 1,2‐bis(4‐pyridyl)ethylene (BPE). The designed SERS substrate yields an average enhancement factor of 3.2 × 106 while maintaining reproducibility characteristics as good as 94% over the sensing region of the substrate. The usability of the designed SERS substrate has been demonstrated through the detection and analysis of purified rotavirus double‐stranded RNA (dsRNA) samples in the laboratory environment condition. Rotavirus RNA concentrations as low as 10 ng/μL could be detected with the proposed sensing scheme.
100 GSM paper as an SERS substrate for trace detection of pharmaceutical drugs in an aqueous medium Dipjyoti Sarma, Sritam Biswas, Diganta Hatiboruah, Nabadweep Chamuah, Pabitra Nath Journal of Physics D Applied Physics, 2022 Surface-enhanced Raman spectroscopy (SERS) is a unique technique that allows us to detect samples in trace quantities. The spectral intensities of the characteristic Raman peaks of the analyte molecule are enhanced manifold in the presence of noble metal nanoparticles (NPs). The existence of NPs is necessary to couple the incident electromagnetic field with NPs through the localized surface plasmon resonance phenomenon, which primarily contributes to the enhancement of an SERS signal. The present work demonstrates the working of a paper-based SERS substrate to detect and quantify two pharmaceutical drugs—paracetamol and aspirin—in water. The proposed SERS substrate was obtained by drop-casting silver NPs over printing grade 100 grams per square meter (GSM) paper. 100 GSM denotes the class of paper where 100 grams of raw materials (cellulose) is used per square meter to manufacture the paper. The performance of the designed SERS substrate was initially evaluated with two Raman active samples—malachite green and rhodamine-6G. The applicability of the proposed SERS substrate was evaluated further through monitoring the Raman spectra of the two aforementioned pharmaceutical drugs in different field-collected water samples, thus establishing the reliability of the scheme in a real field environment.
Blue-ray DVD as a low-cost substrate for the fast sensing of paracetamol in aqueous medium using surface-enhanced Raman spectroscopy (SERS) Dipjyoti Sarma, Sritam Biswas, Pabitra Nath 2022 Workshop on Recent Advances in Photonics Wrap 2022, 2022 Surface-Enhanced Raman Scattering (SERS) is an analytical tool for rapid sensing of analytes. We here report the working of a highly sensitive and reproducible SERS substrate by effective guidance of localized plasmon resonance (LSPR) field of silver nanoparticles (AgNPs) trapped in the nano channels of Blue-ray DVD (BR-DVD). The trapped AgNPs in the channels of BR-DVD generate Guided mode resonance (GMR) field. The designed substrate is used for the trace sensing of paracetamol in aqueous medium. The minimum concentration detected is 0.1 mM.
