Lotey Navjeet Kaur B, Lemos Romila, D'Silva Fayth, Deshmukh Amol, Singh Nrashant, Wankhede Siddharth, Davuluri Rohita, Vishe Neha, Kulkarni Samir
Institute of Chemical Technology, Matunga, Mumbai, India.
Institute of Forensic Science, Mumbai, India.
J Fluoresc. 2025 Jan 7. doi: 10.1007/s10895-024-04107-8.
This study introduces an innovative approach to high-resolution latent fingerprint detection using carbon quantum dots (CQDs) biosynthesized from spent coffee grounds, enhanced with nitrogen doping. Conventional fingerprinting methods frequently use hazardous chemicals and are costly, highlighting the need for eco-friendly, affordable alternatives that preserve detection quality. The biosynthesized nitrogen-doped CQDs exhibit strong photoluminescence and high stability, offering a sustainable, effective alternative for fingerprint imaging. Using a one-step hydrothermal synthesis method, nitrogen-doped CQDs were developed, displaying intense cyan fluorescence under UV light at 365 nm. The quantum yield was measured to be 19.73%. Characterization through UV-Visible and photoluminescence spectroscopy, FTIR, XRD and TEM confirmed the morphology, surface properties, optical properties and stability. The average particle size diameter was calculated to be around 8.71 ± 0.14 nm. These CQDs were tested on various non-porous surfaces including marble, glass, aluminium, and metal where they provided detailed visualization of fingerprint ridge patterns, sweat pores, and minutiae with high fluorescence. Notably, the CQDs demonstrated excellent adherence and sustained fluorescence, maintaining photostability for up to 60 days under dark storage conditions at 2-8 °C. This sustainable synthesis method thus produces nitrogen-doped CQDs with robust fluorescent properties, establishing a promising, eco-friendly solution for high-resolution latent fingerprint detection in forensic investigations.
本研究介绍了一种创新方法，用于使用从废弃咖啡渣生物合成的碳量子点（CQD）进行高分辨率潜指纹检测，并通过氮掺杂进行增强。传统的指纹识别方法经常使用有害化学物质且成本高昂，这凸显了对环保、经济实惠且能保持检测质量的替代方法的需求。生物合成的氮掺杂CQD表现出强烈的光致发光和高稳定性，为指纹成像提供了一种可持续、有效的替代方案。采用一步水热合成法制备了氮掺杂CQD，在365nm紫外光下呈现强烈的青色荧光。测得量子产率为19.73%。通过紫外可见光谱和光致发光光谱、傅里叶变换红外光谱、X射线衍射和透射电子显微镜进行表征，证实了其形态、表面性质、光学性质和稳定性。计算得出平均粒径约为8.71±0.14nm。这些CQD在包括大理石、玻璃、铝和金属在内的各种无孔表面上进行了测试，它们能以高荧光清晰显示指纹纹路、汗孔和细节特征。值得注意的是，CQD表现出优异的附着力和持续荧光，在2-8°C的黑暗储存条件下，光稳定性可维持长达60天。因此，这种可持续合成方法制备出具有强大荧光特性的氮掺杂CQD，为法医调查中的高分辨率潜指纹检测建立了一种有前景的、环保的解决方案。
