Dr Rajapandiyan P, Associate Professor, Department of Chemistry, and his PhD scholar, Ms Arunima Jinachandran, recently filed and published a patent, “A Substrate for Contaminant Detection and a Process for its Synthesis,” with Application Number: 202441043642 in the Patent Office Journal. The research duo has developed a novel SERS (Surface-Enhanced Raman Spectroscopy) substrate by synthesising silver nanopopcorn and depositing it on a polycarbonate membrane.
This novel substrate demonstrates excellent uniformity, reproducibility, and mechanical stability. It is used for the sensitive detection of toxic antibiotic nitrofurazone on fish surfaces and in honey. This breakthrough could significantly enhance food safety monitoring by providing a reliable and efficient method for detecting harmful substances.
Abstract
Detecting nitrofurazone (NFZ) in aquaculture and livestock is crucial due to its carcinogenic properties. This study presents a flexible polycarbonate membrane (PCM) with three-dimensional silver nanopopcorns (Ag NPCs) for NFZ detection on fish surfaces using surface-enhanced Raman spectroscopy (SERS). The Ag-NPCs/PCM substrate demonstrates a significant Raman signal enhancement (EF = 2.36 × 106) due to hotspots from nanoscale protrusions and crevices. It achieves a low limit of detection (LOD) of 3.7 × 10−9 M, with uniform and reproducible signals (RSD < 8.34%) and retains 70% efficacy after 10 days. The practical detection LODs for NFZ in tap water, honey water, and on fish surfaces are 1.35 × 10−8 M, 5.76 × 10−7 M, and 3.61 × 10−8 M, respectively, demonstrating its effectiveness for various samples. This Ag-NPCs/PCM substrate offers a promising approach for sensitive SERS detection of toxic substances in real-world applications.
Practical Implementation/ Social Implications of the Research
The practical applicability of the proposed Ag-NPCs/PCM SERS substrate is validated by successfully detecting NFZ in various actual samples, such as tap water, honey water, and irregular fish surfaces.
Collaborations – Prof. Tzyy-Jiann Wang – National Taipei University of Technology, Taiwan
Dr Rajapandiyan and Ms Arunima will continue to work towards the development of novel flexible SERS substrates for detecting toxic pollutants in food.
Continue reading →As part of the 13th edition of the Bengaluru India Nano 2024, heralded by Bharat Ratna recipient and renowned chemist Prof. C N R Rao, SRM University-AP hosted “Nano Jatha“, an intensive science outreach programme, catering to educate undergraduate graduates on the emerging trends of nanotechnology, on July 20, 2024. The Nano Jatha programme organised, aimed to raise awareness on nanoscience and technology through technical presentations by expert scientists and a distinctive live experiment demonstration of nano kits focused on showcasing nanoscience ideas.
The event featured two expert talks by eminent dignitaries. Prof. B L V Prasad, Director-Centre for Nano and Soft Matter Sciences (CeNS), Department of Science and Technology, Govt. of India, also serving as the Nodal Officer for organising Nano Jatha events, delivered a session on the introduction to nanoscience and technology. “Nanoscience and technology are often foretold as the technology of the future. This multidimensional technology will revolutionise our understanding of every natural phenomenon and every aspect of human life,” remarked Prof. Prasad in his session.
Prof. C P Rao, Senior Professor at the Department of Chemistry, presented the second expert talk on the applications of nanomaterials. The session delved into the properties of covalent molecules and its assemblage leading to cutting-edge technology. The programme also featured an exhibition were experiments on Gold nanoparticle; Galvanization reaction between metals; Piezoelectric pavement for futuristic applications; Humidity sensors for real-world applications and many more were displayed.
Prof. C V Tomy, Dean-School of Engineering & Sciences and Dr Pardha Saradhi Maram, Head-Department of Chemistry, emphasised that the Nano Jatha exemplified the university’s commitment to hands-on learning in science, specifically nanotechnology.They commented that the Department of Chemistry is dedicated to fostering scientific knowledge and igniting passion for chemistry among students and educators alike and will continue to organise events like Nano Jatha, conferences, workshops, and Faculty Development Programmes to achieve the same.
Over 300 students from 7 regional colleges in Andhra Pradesh participated in the programme, displaying their zeal in the discussions and nano kit demonstrations. The event was well executed benefitting the student community significantly in understanding various emerging fields in science and technology.
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Dr Chinmoy Das, Assistant Professor at the Department of Chemistry at SRM University-AP, has made an impactful contribution with the publication of his research paper, “Insights into the Mechanochemical Glass Formation of Zeolitic Imidazolate Frameworks” in the prestigious Angewandte Chemie International Edition with an impact factor of 16.6. His paper unveils a rapid, eco-friendly, and efficient mechanochemical approach to transform glasses from their crystalline zeolitic imidazolate frameworks. This pioneering work opens new doors for sustainable and effective glass formation, showcasing the power of innovation in the field of chemistry.
Abstract:
We describe a rapid, ecofriendly, and efficient mechanochemical approach to transform glasses from their crystalline zeolitic imidazolate frameworks (ZIFs). We exposition mechanochemical technique through which the traditional melt-quench preparation of glassy phases can be replaced. In this study, we explore that Zn(II), Co(II), and Cu(II)- based crystalline ZIFs transformed into the glassy phases within five minutes through the mechanical ball milling technique. The appearance of glass transition temperature(T g ) upon mechanical milling of crystalline states demonstrated by different characterization techniques, such as X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), simultaneous thermogravimetric and differential thermal analyses (TG/DTA), scanning electron microscopy (SEM), X-ray total scattering and its deduced pair distribution functions (PDFs). We characterized the porosity and density of the glassy phases through CO 2 gas sorption techniques which aligned with the observation of thermal, structural, and textural features of the ZIFs after varying ball milling times beyond five minutes.
Practical implementation
We can prepare bulk ZIF glasses within five minutes of the mechanochemical approach that will guide the greater feasibility to produce the glass materials for industrial implications. In addition, the greater the accessibility of glassy materials, the greater the fabrication of glassy materials-based device fabrication.
Collaborations
This article has been published with the collaboration of Prof. Sebastian Henke (Henke Group), Department of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany.
Future Research Plans
Recently, we established our research group in SRM University-AP, and our group has started to explore an emergent research area of crystal-glass composite materials towards the applications of atmospheric water harvesting, solid-state electrolytes (Alkali and Alkaline metal ions-based), photovoltaics, and conversion of gaseous Carbon-dioxide molecules to industrially relevant liquids, such as methanol or ethanol.
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The Department of Chemistry and RARE Lab are excited to announce a groundbreaking advancement in the field of analytical detection. Researchers Dr Rajapandiyan Panneerselvan, Asst. Professor and Ph.D scholars, Ms Arunima Jinachandran and Ms Jayasree Kumar have developed a novel method for detecting nitrofurazone (NFZ) using three-dimensional silver nanopopcorns (Ag NPCs) on a flexible polycarbonate membrane (PCM) in their paper “Silver nanopopcorns decorated on flexible membrane for SERS detection of nitrofurazone” published in Microchimica Acta. This innovative technique leverages the power of surface-enhanced Raman spectroscopy (SERS) to provide a highly sensitive and practical solution for detecting NFZ on various surfaces, including fish.
Nitrofurazone (NFZ) is an antibiotic commonly used in veterinary medicine that poses significant health risks if residues enter the food chain. Despite regulatory bans, its illegal use continues, necessitating highly sensitive detection methods. While effective, traditional methods such as high-performance liquid chromatography and mass spectrometry are often costly and labor-intensive. The new SERS-based method offers a more efficient and straightforward alternative.
Abstract
The synthesis of three-dimensional silver nanopopcorns (Ag NPCs) onto a flexible polycarbonate membrane (PCM) for the detection of nitrofurazone (NFZ) on fish surfaces by surface-enhanced Raman spectroscopy (SERS) is presented. The proposed flexible Ag-NPCs/PCM SERS substrate exhibits significant Raman signal intensity enhancement with a measured enhancement factor of 2.36 × 10^6. This enhancement is primarily attributed to the hotspots created on Ag NPCs, which include numerous nanoscale protrusions and internal crevices distributed across the surface. The detection of NFZ using this flexible SERS substrate demonstrates a low limit of detection (LOD) of 3.7 × 10^−9 M and uniform, reproducible Raman signal intensities with a relative standard deviation below 8.34%. The substrate also exhibits excellent stability, retaining 70% of its efficacy even after 10 days of storage. Notably, the practical detection of NFZ in tap water, honey water, and fish surfaces achieves LOD values of 1.35 × 10^−8 M, 5.76 × 10^−7 M, and 3.61 × 10^−8 M, respectively, highlighting its effectiveness across different sample types. The developed Ag-NPCs/PCM SERS substrate presents promising potential for the sensitive SERS detection of toxic substances in real-world samples.
Methodology
The synthesis involves creating silver nanopopcorns on a flexible polycarbonate membrane using a simple chemical method. The resulting Ag NPCs exhibit high surface roughness with numerous nanoscale features that enhance the Raman signal. This flexible substrate can easily collect samples from irregular surfaces without requiring extensive preparation.
This SERS substrate can detect NFZ in various real-world samples, including:
The method’s sensitivity and ease of use make it a promising tool for ensuring food safety and monitoring environmental contaminants.
The Department believes this development will significantly impact public health by providing a reliable and accessible method for detecting harmful substances in the food chain.
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