COVALENT ORGANIC FRAMEWORK (COF) BASED APTAMER CLOSED LOOP SYSTEM TO COMBAT ANTIBACTERIAL RESISTANCE ABSTRACT The antimicrobial resistance (AMR) is a global crisis in terms of healthcare that needs immediate attention. The misuse and overuse of antibiotics for various purposes has led to teh organsims developing resistance to it. Recently, biosensor mediated drug delivery systems have come into foreplay to combat AMR, also called as closed loop systems. These systems detects the presence of AMR-producing bacteria, proteins or AMR genes itself in a sample (e.g., wastewater or clinical sample, site of wound) but also triggers a response—such as releasing a neutralizing agent or drug or activating a downstream warning system. In this study a covalent organic framework(COF) functionalised with endolysin derived cell wall binding domain (CBD) binding to receptors and aptamers specific for the mecA genes(S.aureus) of AMR bacteria and siRNA within its cavity based biosensor is injected at the site of infection. The aptamer conjugated to a fluorescent dye fluoresceses on target binding and aptamer conformational change. This triggers the COF to release the siRNA that neutralizes the AMR gene. The biosensor aims to generate a highly sensitive, specific, rapidly detecting system that not only detects the biomarkers but also instantaneously produces a feedback treatment mechanism. The system can be used to detect proteins and toxins produced by the resistant bacteria by replacing the specific aptamers for the specific targets.