Ma, Xiao-MengWang, Jian-WeiZhao, Li-TingZhang, YafeiLiu, Jun-YingWang, SongmeiZhu, DaochenYang, ZhugenYong, Yang-Chun2023-02-152023-02-152023-01-27Ma XM, Wang JW, Zhao LT, et al., (2023) Self-assembled microfiber-like biohydrogel for ultrasensitive whole-cell electrochemical biosensing in microdroplets, Analytical Chemistry, Volume 95, Issue 5, February 2023, pp. 2628-26320003-2700https://doi.org/10.1021/acs.analchem.2c05155https://dspace.lib.cranfield.ac.uk/handle/1826/19182A novel microfiber-like biohydrogel was fabricated by a facile approach relying on electroactive bacteria-induced graphene oxide reduction and confined self-assembly in a capillary tube. The microfiber-like biohydrogel (d = ∼1 mm) embedded high-density living cells and activated efficient electron exchange between cells and the conductive graphene network. Further, a miniature whole-cell electrochemical biosensing system was developed and applied for fumarate detection under −0.6 V (vs Ag/AgCl) applied potential. Taking advantage of its small size, high local cell density, and excellent electron exchange, this microfiber-like biohydrogel-based sensing system reached a linear calibration curve (R2 = 0.999) ranging from 1 nM to 10 mM. The limit of detection obtained was 0.60 nM, which was over 1300 times lower than a traditional biosensor for fumarate detection in 0.2 μL microdroplets. This work opened a new dimension for miniature whole-cell electrochemical sensing system design, which provided the possibility for bioelectrochemical detection in small volumes or three-dimensional local detection at high spatial resolutions.enAttribution-NonCommercial 4.0 InternationalArticle1520-6882