School of Agricultural and Food Science, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou 311300, China.
State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Biosens Bioelectron. 2017 Nov 15;97:278-284. doi: 10.1016/j.bios.2017.06.009. Epub 2017 Jun 7.
The near-infrared (NIR) optical detection of biomolecules with high sensitivity and reliability have been expected, however, it is still a challenge. In this work, we present a gold nanorods (AuNRs)-over-gallium arsenide nanohorn-like array (GaAs NHA) system that can be used for the ultrasensitive and specific NIR photoluminescence (PL) detection of DNA and proteins. The fabrication of GaAs NHA involved the technique of colloidal lithography and inductively coupled plasma dry etching, yielding large-area and well-defined nanostructural array, and exhibiting an improved PL emission compared to the planar GaAs substrate. Importantly, we found that the DNA-bridged AuNRs attachment on NHA could further improve the PL intensity from GaAs, and thereby provide the basis for the NIR optical sensing of biological analytes. We demonstrated that DNA and thrombin could be sensitively and specifically detected, with the detection limit of 1 pM for target DNA and 10 pM for thrombin. Such ultrasensitive NIR optical platform can extend to the detection of other biomarkers and is promising for clinical diagnostics.
人们一直期望能够实现具有高灵敏度和可靠性的近红外（NIR）光学检测生物分子，然而，这仍然是一个挑战。在这项工作中，我们提出了一个金纳米棒（AuNRs）-覆盖砷化镓纳米角状阵列（GaAs NHA）系统，可用于超灵敏和特异性的近红外光致发光（PL）检测 DNA 和蛋白质。GaAs NHA 的制备涉及胶体光刻和感应耦合等离子体干法刻蚀技术，可获得大面积和良好定义的纳米结构阵列，并表现出比平面 GaAs 衬底更好的 PL 发射。重要的是，我们发现 DNA 桥接的 AuNRs 附着在 NHA 上可以进一步提高 GaAs 的 PL 强度，从而为生物分析物的近红外光学传感提供了基础。我们证明了 DNA 和凝血酶可以被灵敏和特异性地检测到，目标 DNA 的检测限为 1 pM，凝血酶的检测限为 10 pM。这种超灵敏的近红外光学平台可以扩展到其他生物标志物的检测，有望用于临床诊断。
