Biosensor Development Laboratory, Department of Biotechnology, Punjabi University, Patiala, 147002, Punjab, India.
Appl Biochem Biotechnol. 2013 Nov;171(6):1405-15. doi: 10.1007/s12010-013-0429-2. Epub 2013 Aug 18.
An ultrasensitive fluorimetric biosensor for the detection of chemical warfare agent sulfur mustard (SM) was developed using its monofunctional analogue. SM is a vesicant and a potent chemical threat owing to its direct toxic effects on eyes, lungs, skin and DNA. This work investigates the quenching action of the analyte on chlorophyll fluorescence as elucidated by nuclear magnetic resonance, Fourier transform infrared spectroscopy and mass spectrometry studies suggesting the electrophilic attack of carbonium ion on nitrogens of the porphyrin moiety of chlorophyll. The properties of immobilisation matrix were optimised and scanning electron microscope observations confirmed improvement in pore size of sol-gels by addition of 32 % (v/v) glycerol, a feature enabling enhanced sensitivity towards the analyte. Chlorophyll embedded sol-gel was treated with increasing concentrations of monofunctional SM and the corresponding drop in maximum fluorescence intensity as measured by emission at 673 nm was observed, which varied linearly and had a detection limit of 7.68 × 10(-16) M. The biosensor was found to be 6 orders of magnitude more sensitive than the glass microfibre-based disc biosensor previously reported by us.
一种超灵敏的荧光生物传感器，用于检测化学战剂芥子气（SM），使用其单官能类似物开发。SM 是一种水疱剂，也是一种强大的化学威胁，因为它直接对眼睛、肺部、皮肤和 DNA 产生毒性作用。这项工作通过核磁共振、傅里叶变换红外光谱和质谱研究，研究了分析物对叶绿素荧光的猝灭作用，表明碳正离子对叶绿素卟啉部分的氮的亲电攻击。优化了固定化基质的性质，并通过添加 32%（体积/体积）甘油观察到溶胶-凝胶的孔径得到改善，这一特性使传感器对分析物的灵敏度得到增强。将叶绿素嵌入的溶胶-凝胶用递增浓度的单官能 SM 处理，并观察到最大荧光强度的相应下降，通过在 673nm 处的发射进行测量，该强度呈线性变化，检测限为 7.68×10(-16)M。与我们之前报道的基于玻璃微纤维的圆盘生物传感器相比，该生物传感器的灵敏度高 6 个数量级。
