Spatially resolved charge-transfer kinetics at the quantum dot-microbe interface using fluorescence lifetime imaging microscopy

• 成果类型: Article
• 署名作者: Suri, Mokshin; Jazi, Farshid Salimi; Crowley, Jack C.; Park, Youngchan; Fu, Bing; Chen, Peng; Zipfel, Warren R.; Barstow, Buz; Hanrath, Tobias
• 署名单位: Cornell University; Cornell University; Cornell University; Cornell University; Cornell University; Cornell University; City University of Hong Kong
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15301
• DOI: 10.1073/pnas.2407987122
• 发表日期: 2025-03-17
• 关键词: extracellular electron-transport; shewanella-oneidensis mr-1; bacterial nanowires; outer-membrane; cds nanorods; cdte; reduction; ligands; flavins

摘要

Integrating the optoelectronic properties of quantum dots (QDs) with biological enzymatic systems to form microbe-semiconductor biohybrids offers promising prospects for both solar-to-chemical conversion and light-modulated biochemical processes. Developing these nano-bio hybrid systems necessitates a deep understanding of charge-transfer dynamics at the nano-bio interface. Photoexcited carrier transfer from QDs to microbes is driven by complex interactions, with emerging insights into the relevant thermodynamic and kinetic factors. The heterogeneities of both microbes and QD ensembles pose significant challenges in mechanistic understanding, which is critical for designing advanced nano-bio hybrids. We used fluorescence lifetime imaging microscopy to analyze charge transfer between a CdSe QD film and Shewanella oneidensis microbes. We correlated the spatiotemporal fluorescence data with an analytical model. Our analysis revealed two distinct distributions of QD de-excitation pathways. The characteristics of these distributions: 1) a faster transfer rate (kET 1 = 1.5 (109) s-1), with a lower acceptor number (Na1 = 0.03 ) and 2) a slower transfer rate (kET 2 = 4.1 (108) s-1) with a higher acceptor number (Na2 = 0.18 ). We assign these distributions to the indirect and direct electron transfer mechanisms, respectively. Our findings demonstrate how spectroscopic imaging can uncover fundamental electron transfer mechanisms at complex interfaces, offering valuable design principles for future nano-bio hybrids.