Biomedical Engineering program, University of Victoria, Victoria, BC V8W 2Y2, Canada.
Department of Mechanical Engineering, University of Victoria, Victoria, BC V8W 2Y2, Canada.
Biosensors (Basel). 2017 Aug 5;7(3):31. doi: 10.3390/bios7030031.
This work developed a prototype of an affordable, long-term water quality detection device that provides a visual readout upon detecting bacterial contamination. This device prototype consists of: (1) enzyme-releasing microspheres that lyse bacteria present in a sample, (2) microspheres that release probes that bind the DNA of the lysed bacteria, and (3) a detector region consisting of gold nanoparticles. The probes bind bacterial DNA, forming complexes. These complexes induce aggregation of the gold nanoparticles located in the detector region. The nanoparticle aggregation process causes a red to blue color change, providing a visual indicator of contamination being detected. Our group fabricated and characterized microspheres made of poly (ε-caprolactone) that released lysozyme (an enzyme that degrades bacterial cell walls) and hairpin DNA probes that bind to regions of the genome over a 28-day time course. The released lysozyme retained its ability to lyse bacteria. We then showed that combining these components with gold nanoparticles followed by exposure to an -contaminated water sample (concentrations tested-10⁶ and 10⁸ cells/mL) resulted in a dramatic red to blue color change. Overall, this device represents a novel low-cost system for long term detection of bacteria in a water supply and other applications.
这项工作开发了一种经济实惠、可长期进行水质检测的设备原型，该设备在检测到细菌污染时会提供直观的读数。该设备原型由以下三部分组成：(1) 释放酶的微球，可裂解样本中的细菌；(2) 释放与裂解细菌的 DNA 结合的探针的微球；(3) 由金纳米颗粒组成的检测区。探针与细菌 DNA 结合，形成复合物。这些复合物诱导位于检测区的金纳米颗粒聚集。纳米颗粒的聚集过程导致颜色从红色变为蓝色，提供了正在检测的污染的视觉指示。我们小组制造并表征了由聚己内酯制成的微球，这些微球在 28 天的时间内释放溶菌酶（一种降解细菌细胞壁的酶）和发夹 DNA 探针，这些探针与基因组的特定区域结合。释放的溶菌酶保持裂解细菌的能力。然后，我们表明，将这些成分与金纳米颗粒结合，然后暴露于受污染的水样（测试浓度为 10⁶ 和 10⁸ 个细胞/毫升）中，会导致明显的从红色到蓝色的颜色变化。总的来说，该设备代表了一种新颖的低成本系统，可用于长期检测供水和其他应用中的细菌。
