Photonic crystal enhanced fluorescence immunoassay on diatom biosilica
Photonic crystal enhanced fluorescence immunoassay on diatom biosilica
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DOI：
10.1002/jbio.201800009
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发表时间：
2018-06
影响因子：
2.8
通讯作者：
Kenneth J. Squire;Xianming Kong;Paul Leduff;G. Rorrer;Alan X. Wang
中科院分区：
文献类型：
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作者：
Kenneth J. Squire;Xianming Kong;Paul Leduff;G. Rorrer;Alan X. Wang
荧光生物传感是最成熟的生物传感方法之一，特别是荧光光谱和显微镜。这是两种高灵敏度的技术，但需要高等级的电子和光学器件来实现所需的灵敏度。人们已经努力使用消费级电子设备和简单的光学设置来实现这些方法，用于诸如床旁诊断的应用，但是灵敏度固有地受到影响。因此，需要能够增强荧光的感测基底以实现用于此类应用的高灵敏度。在本文中，我们展示了一种光子晶体增强的荧光免疫生物传感器，使用硅藻生物二氧化硅，它由具有亚100 nm周期性孔的二氧化硅硅藻壳组成。利用增强的局部光场，珀塞尔效应和增加的表面积从硅藻光子晶体，我们创建超灵敏的免疫测定生物传感器，可以显着增强荧光光谱以及荧光成像。使用标准抗体-抗原-标记抗体免疫测定方案，我们通过荧光光谱和荧光成像分别实现了100倍和10倍的检测限。对于两种检测模式，小鼠IgG的检测限分别降至10 - 16 M（14 fg/mL）和10 - 15 M（140 fg/mL），实际上在每个硅藻硅藻壳上检测到单个小鼠IgG分子。本文中使用的有效增强的荧光成像结合简单的热点计数分析方法证明了硅藻荧光免疫测定在床旁生物传感方面的巨大潜力。
Fluorescence biosensing is one of the most established biosensing methods, particularly fluorescence spectroscopy and microscopy. These are two highly sensitive techniques but require high‐grade electronics and optics to achieve the desired sensitivity. Efforts have been made to implement these methods using consumer grade electronics and simple optical setups for applications such as point‐of‐care diagnostics, but the sensitivity inherently suffers. Sensing substrates, capable of enhancing fluorescence are thus needed to achieve high sensitivity for such applications. In this paper, we demonstrate a photonic crystal‐enhanced fluorescence immunoassay biosensor using diatom biosilica, which consists of silica frustules with sub‐100 nm periodic pores. Utilizing the enhanced local optical field, the Purcell effect and increased surface area from the diatom photonic crystals, we create ultrasensitive immunoassay biosensors that can significantly enhance fluorescence spectroscopy as well as fluorescence imaging. Using standard antibody‐antigen‐labeled antibody immunoassay protocol, we experimentally achieved 100× and 10× better detection limit with fluorescence spectroscopy and fluorescence imaging respectively. The limit of detection of the mouse IgG goes down to 10−16 M (14 fg/mL) and 10−15 M (140 fg/mL) for the two respective detection modalities, virtually sensing a single mouse IgG molecule on each diatom frustule. The effectively enhanced fluorescence imaging in conjunction with the simple hot‐spot counting analysis method used in this paper proves the great potential of diatom fluorescence immunoassay for point‐of‐care biosensing.