Bioelectronic Platform to Investigate Charge Transfer between Photoexcited Quantum Dots and Microbial Outer Membranes.
Mokshin SuriZeinab MohamedSamavi Farnush Bint E NaserXianwen MaoPeng ChenSusan DanielTobias HanrathPublished in: ACS applied materials & interfaces (2022)
Photosynthetic semiconductor biohybrids (PSBs) convert light energy to chemical energy through photo-driven charge transfer from nanocrystals to microorganisms that perform bioreactions of interest. Initial proof-of-concept PSB studies with an emphasis on enhanced CO 2 conversion have been encouraging; however, bringing the broad prospects of PSBs to fruition is contingent on establishing a firm fundamental understanding of underlying interfacial charge transfer processes. We introduce a bioelectronic platform that reduces the complexity of PSBs by focusing explicitly on interactions between colloidal quantum dots (QDs), microbial outer membranes, and native, small-molecule redox mediators. Our model platform employs a standard three-electrode electrochemical cell with supported outer membranes of Pseudomonas aeruginosa , pyocyanin redox mediators, and semiconducting CdSe QDs dispersed in an aqueous electrolyte. We present a comprehensive electrochemical analysis of this platform via electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA). EIS reveals the formation and electronic properties of supported outer membrane films. CV reveals the electrochemically active surface area of P. aeruginosa outer membranes and that pyocyanin is the sole species that performs redox with these outer membranes under sweeping applied potential. CA demonstrates that photoexcited charge transfer in this system is driven by the reduction of pyocyanin at the QD surface followed by diffusion of reduced pyocyanin through the outer membrane. The broad applicability of this platform across many bacterial species, QD architectures, and controlled environmental conditions affords the possibility to define design principles for future PSB systems to synergistically integrate concurrent advances in genetically engineered organisms and inorganic nanomaterials.
Keyphrases
- quantum dots
- ionic liquid
- electron transfer
- high throughput
- small molecule
- room temperature
- gold nanoparticles
- pseudomonas aeruginosa
- microbial community
- molecularly imprinted
- cystic fibrosis
- energy transfer
- magnetic resonance imaging
- label free
- drug resistant
- single cell
- staphylococcus aureus
- magnetic resonance
- stem cells
- mesenchymal stem cells
- mass spectrometry
- protein kinase
- acinetobacter baumannii
- squamous cell carcinoma
- carbon nanotubes
- gram negative
- climate change
- risk assessment
- contrast enhanced
- perovskite solar cells