Nanomedicine Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Nanomedicine Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Biosens Bioelectron. 2021 Jul 15;184:113244. doi: 10.1016/j.bios.2021.113244. Epub 2021 Apr 15.
Smart biocompatible materials, responsive to various external stimuli, hold immense potential in the development of biosensors for low-cost diagnostics. The present paper outlines the development of smart enzyme-responsive core-shell nanoparticle-based sensors as low-cost diagnostics for alpha amylase detection. The biocompatible core-shell nanoparticles of 200-250 nm size consisted of a chitosan-tripolyphosphate core formed by ionic gelation coated with a starch-iodine shell. In the presence of specific concentrations of amylase, the starch-iodine shell was disrupted and resulted in the exposure of core. This application herein describes a visible switch in color from blue to red towards the point-of-care detection of salivary alpha amylase (sAA). Stress and other autonomic disturbances can be diagnosed by measuring this biomarker. Also, alpha amylase can be used in the detection of latent saliva at crime scenes for forensic investigations. Using the present platform technology, a paper-based diagnostic was developed for detection of salivary alpha amylase that demonstrated a limit of detection (LoD) of 140 units/ml (70 mg/ml) at 5 minutes while a coated swab developed from the nanoparticles for crime scene investigations could achieve an LoD of 2.5 units/ml (1.25 mg/ml) over 30 minutes. The nanoparticles demonstrated stability and reproducibility with no interference seen with other substances in saliva. The present paper provides a proof-of-concept technology underscoring the utility of smart nanoparticles in affordable, versatile biosensing platforms like paper-based and swab-based formats for such diverse applications as diagnostics for stress and in forensics.
智能生物相容性材料，对各种外部刺激做出响应，在开发用于低成本诊断的生物传感器方面具有巨大潜力。本文概述了智能酶响应核壳纳米粒子基传感器的开发，作为用于检测α-淀粉酶的低成本诊断方法。生物相容性的核壳纳米粒子大小为 200-250nm，由通过离子凝胶形成的壳聚糖-三聚磷酸酯核组成，该核上涂覆有淀粉-碘壳。在存在特定浓度的淀粉酶的情况下，淀粉-碘壳被破坏，导致核暴露。本文描述了一种可见的颜色从蓝色到红色的开关，用于现场即时检测唾液α-淀粉酶（sAA）。通过测量这种生物标志物，可以诊断压力和其他自主神经紊乱。此外，α-淀粉酶可用于检测犯罪现场潜在的唾液，用于法医调查。使用本研究的平台技术，开发了用于检测唾液α-淀粉酶的基于纸的诊断方法，在 5 分钟时检测限（LoD）为 140 单位/ml（70mg/ml），而从纳米粒子开发的用于犯罪现场调查的涂层拭子在 30 分钟内可以达到 2.5 单位/ml（1.25mg/ml）的 LoD。纳米粒子表现出稳定性和重现性，在唾液中没有观察到其他物质的干扰。本文提供了一个概念验证技术，强调了智能纳米粒子在负担得起的、多功能生物传感平台（如基于纸和拭子的格式）中的实用性，用于各种应用，如压力诊断和法医学。
