Multimodal Biofilm Inactivation Using a Photocatalytic Bismuth Perovskite-TiO2-Ru(II)polypyridyl-Based Multisite Heterojunction

Noufal Kandoth*, Sonu Pratap Chaudhary, Shresth Gupta, Kumari Raksha, Atin Chatterjee, Shresth Gupta, Safakath Karuthedath, Catherine S.P. De Castro, Frédéric Laquai, Sumit Kumar Pramanik, Sayan Bhattacharyya*, Amirul Islam Mallick*, Amitava Das*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Infectious bacterial biofilms are recalcitrant to most antibiotics compared to their planktonic version, and the lack of appropriate therapeutic strategies for mitigating them poses a serious threat to clinical treatment. A ternary heterojunction material derived from a Bi-based perovskite-TiO2hybrid and a [Ru(2,2′-bpy)2(4,4′-dicarboxy-2,2′-bpy)]2+(2,2′-bpy, 2,2′-bipyridyl) as a photosensitizer (RuPS) is developed. This hybrid material is found to be capable of generating reactive oxygen species (ROS)/reactive nitrogen species (RNS) upon solar light irradiation. The aligned band edges and effective exciton dynamics between multisite heterojunctions are established by steady-state/time-resolved optical and other spectroscopic studies. Proposed mechanistic pathways for the photocatalytic generation of ROS/RNS are rationalized based on a cascade-redox processes arising from three catalytic centers. These ROS/RNS are utilized to demonstrate a proof-of-concept in treating two elusive bacterial biofilms while maintaining a high level of biocompatibility (IC50> 1 mg/mL). The in situ generation of radical species (ROS/RNS) upon photoirradiation is established with EPR spectroscopic measurements and colorimetric assays. Experimental results showed improved efficacy toward biofilm inactivation of the ternary heterojunction material as compared to their individual/binary counterparts under solar light irradiation. The multisite heterojunction formation helped with better exciton delocalization for an efficient catalytic biofilm inactivation. This was rationalized based on the favorable exciton dissociation followed by the onset of multiple oxidation and reduction sites in the ternary heterojunction. This together with exceptional photoelectric features of lead-free halide perovskites outlines a proof-of-principle demonstration in biomedical optoelectronics addressing multimodal antibiofilm/antimicrobial modality.

Original languageEnglish (US)
Pages (from-to)10393-10406
Number of pages14
JournalACS Nano
Issue number11
StatePublished - Jun 13 2023


  • bacterial biofilm
  • bismuth perovskite halides
  • multiheterojunction
  • ruthenium polypyridyl complex
  • TiO

ASJC Scopus subject areas

  • General Materials Science
  • General Engineering
  • General Physics and Astronomy


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