Zero-length crosslinkers are used in reagent systems for bioconjugation.In this project, copolymerized poly-n-isopropylacrylamide (NIPAM) – co – acrylic acid (AAc) [90/10] microgels are the targeted reagent systems for bioconjugation, because of their unique ability to change in size, in direct correlation temperature change. NIPAM-co-AAc microgels, containing 2wt% N,N’methylenebisacrylamide (BIS) crosslinking agent, were synthesized prior via precipitation polymerization. In this work, the carboiimide crosslinking bioconjugation reaction was preformed by crosslinking Alexa Fluro 488 Cadaverine to the carboxylic acid functional groups, on the surface of the microgel particles. The conjugation was initiated by synthesizing 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide (EDC), followed by stabilizing sulfo-NHS ester. The efficacy of this carbodiimide bioconjugation experiment is further verified by quantifying the measuring the fluorescence intensity, as a function of the reacted flurorphor concentration. The fluorescence intensity values were collected on an optical microscope, using image analysis software. The expected results are that fluoresecne intensity will correspond with the initial concentration of added flurophor; thus, will serve as confirmation for successfully conjugating a biomolecule to the surface of the microgel particles. Future work will include conjugating other biomolecules to the surface of the microgels, to investigate their thermo-reversible behavior on flat substrates in preparation to develop them into biosensors.
