A Photonic Crystal Protein Hydrogel Sensor for Candida albicans

作者：Zhongyu Cai, Daniel H. Kwak, David Punihaole, Zhenmin Hong, Sachin Velankar, Xinyu Liu, Sanford A. Asher · 发表于：Angewandte Chemie International Edition · 年份：2015 · DOI：10.1002/anie.201506205 · 被引用次数：179 · 研究领域：Glycosylation and Glycoproteins Research、Biosensors and Analytical Detection、Bacteriophages and microbial interactions

We report two-dimensional (2D) photonic crystal (PC) sensing materials that selectively detect Candida albicans (C. albicans). These sensors utilize Concanavalin A (Con A) protein hydrogels with a 2D PC embedded on the Con A protein hydrogel surface, that multivalently and selectively bind to mannan on the C. albicans cell surface to form crosslinks. The resulting crosslinks shrink the Con A protein hydrogel, reduce the 2D PC particle spacing, and blue-shift the light diffracted from the PC. The diffraction shifts can be visually monitored, measured with a spectrometer, or determined from the Debye diffraction ring diameter. Our unoptimized hydrogel sensor has a detection limit of around 32 CFU/mL for C. albicans. This sensor distinguishes between C. albicans and those microbes devoid of cell-surface mannan such as the gram-negative bacterium E. coli. This sensor provides a proof-of-concept for utilizing recognition between lectins and microbial cell surface carbohydrates to detect microorganisms in aqueous environments.