EMIMBF<sub>4</sub>‑Assisted SnO<sub>2</sub>‑Based Planar Perovskite Films for Label-Free Photoelectrochemical Sensing Jianying Pei Yiping Wu Xiaoyu Guo Ye Ying Ying Wen Haifeng Yang 10.1021/acsomega.7b00496.s001 https://acs.figshare.com/articles/journal_contribution/EMIMBF_sub_4_sub_Assisted_SnO_sub_2_sub_Based_Planar_Perovskite_Films_for_Label-Free_Photoelectrochemical_Sensing/5286028 In this work, a photoelectrochemical (PEC) sensing system was developed for chemical detection without any tags. The system is based on methylammonium lead iodide chloride perovskite as the photoelectrochemical signal-generating molecule, tin oxide nanoparticles (SnO<sub>2</sub>) as the electron transport layer, and ionic liquid of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF<sub>4</sub>) as the stabilizer and electrolyte. The photosensitizer film is formed through spin-coating followed by low-temperature sintering. Upon irradiation with 473 nm light, an anodic photocurrent is generated in a blank electrolyte and changed significantly after addition of hemin into the electrolyte. The change of photocurrent after addition of hemin suggested that the chemicals participated in a photoelectrochemical process. Our work paves the way to developing analytical methods with perovskite. 2017-08-08 17:03:55 SnO 2 tin oxide nanoparticles electrolyte PEC Label-Free Photoelectrochemical photosensitizer film electron transport layer 473 nm light hemin chemical detection photoelectrochemical signal-generating molecule photoelectrochemical process Planar Perovskite Films anodic photocurrent EMIMBF 4 1- ethyl -3-methylimidazolium tetrafluoroborate iodide chloride perovskite