Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Miami, FL 33146, USA.
MP Biomedicals LLC, 3 Hutton Center, Santa Ana, CA 92707, USA.
Molecules. 2019 Sep 9;24(18):3275. doi: 10.3390/molecules24183275.
Nanoparticles have been conjugated to biological systems for numerous applications such as self-assembly, sensing, imaging, and therapy. Development of more reliable and robust biosensors that exhibit high response rate, increased detection limit, and enhanced useful lifetime is in high demand. We have developed a sensing platform by the conjugation of β-galactosidase, a crucial enzyme, with lab-synthesized gel-like carbon dots (CDs) which have high luminescence, photostability, and easy surface functionalization. We found that the conjugated enzyme exhibited higher stability towards temperature and pH changes in comparison to the native enzyme. This enriched property of the enzyme was distinctly used to develop a stable, reliable, robust biosensor. The detection limit of the biosensor was found to be 2.9 × 10 M, whereas its sensitivity was 0.81 µA·mmol·cm. Further, we used the Langmuir monolayer technique to understand the surface properties of the conjugated enzyme. It was found that the conjugate was highly stable at the air/subphase interface which additionally reinforces the suitability of the use of the conjugated enzyme for the biosensing applications.
纳米粒子已与生物系统结合，用于多种应用，如自组装、传感、成像和治疗。开发更可靠和稳健的生物传感器，具有更高的响应速率、增加的检测限和增强的有用寿命，这是非常需要的。我们通过将β-半乳糖苷酶（一种关键酶）与实验室合成的凝胶状碳点（CDs）结合，开发了一种传感平台，这些碳点具有高光致发光、高光稳定性和易于表面功能化的特点。我们发现，与天然酶相比，共轭酶在温度和 pH 值变化方面表现出更高的稳定性。这种酶的富集特性被明显用于开发一种稳定、可靠、稳健的生物传感器。该生物传感器的检测限为 2.9×10-5 M，灵敏度为 0.81µA·mmol·cm。此外，我们使用 Langmuir 单层技术来了解共轭酶的表面性质。结果发现，该共轭物在空气/亚相界面高度稳定，这进一步增强了使用共轭酶进行生物传感应用的适用性。
