Dr Balaji Babu, Assistant Professor, and Dr Sutharsan Govindarajan, Associate Professor from the Department of Biological Sciences at SRM University-AP, along with Mrs Gayathri M P, PhD Scholar from the Department of Chemistry, and Mr Muruganandam Nandhakumar, PhD Scholar from the Department of Biological Sciences, are leading an innovative research study titled “Light Activated Antibacterial Compositions of Triarylphosphonium-Conjugated Tin(IV)-Porphyrins and Their Application Thereof”. Their work focuses on developing a new strategy to combat antibiotic-resistant bacteria, one of the most pressing global health challenges today.
The researchers have developed two special light-activated compounds, BB3 and BB4, that remain harmless in the dark and become active only when exposed to blue light. This makes them safer and more targeted compared to many conventional antibiotic treatments. When activated, these compounds generate highly reactive oxygen molecules that act like microscopic “weapons,” attacking and destroying harmful bacteria, including dangerous drug-resistant strains such as MRSA.
Among the two compounds, BB3 demonstrated remarkable antibacterial efficiency even at extremely low concentrations, while BB4 also showed promising antibacterial activity. Importantly, these compounds are effective against both Gram-positive and Gram-negative bacteria, making them versatile in fighting different types of infections.
Another significant advantage of the research is the fluorescent property of these molecules, which enables scientists to visually track how they move and interact inside bacterial cells. This helps researchers better understand bacterial behavior and improve treatment strategies.
This breakthrough research presents a promising alternative to traditional antibiotics and opens possibilities for future applications in wound healing, skin and dental infections, hospital sterilization, water purification, and food safety. By combining light-based technology with targeted antibacterial action, the study offers a safer and innovative approach to addressing the growing global challenge of antimicrobial resistance.
Brief abstract
Multidrug-resistant (MDR) bacterial infections require alternative therapeutic strategies because effective new antibiotics are limited in availability. Skin and soft-tissue infections, in particular, demand surface-specific treatment approaches such as photo antimicrobial chemotherapy (PACT). We designed and synthesised two structurally related tin(IV)-porphyrins with triphenylphosphonium moieties (BB3, BB4). One of them showed the best performance due to its balanced properties, allowing it to enter bacteria more efficiently. When exposed to blue light, BB3 was highly effective in killing both gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) and gram-negative E. coli bacteria. Overall, the study demonstrates that fine-tuning the chemical structure of these compounds can significantly improve their ability to fight infections.
Practical implementation of your research or the social implications associated with it:
This research can be applied in treating skin and wound infections, dental care, and hospital sterilization using light-activated compounds. It also has potential in water purification and food safety. Socially, it offers a powerful alternative to antibiotics, helping combat antimicrobial resistance with safer, targeted treatments—though its use depends on access to light-based devices.
Future research plans:
Future work will focus on improving the compounds’ performance and safety, testing them in animal and clinical studies, and developing user-friendly formats like creams or coatings. Efforts will also aim to pair them with simple light devices and expand their use in healthcare, sanitation, and environmental applications.
