Sensor development wi̇th BSA (bovi̇ne serum albumi̇n) modified graphane oxide nanoparticles

In this study, a graphene oxide (GO)-based sensor system was developed for the determination of protamine, a biologically important molecule. The study was carried out in a three-stage plan. In the first stage, GO synthesis was carried out using the Modified Hummers method, which is a low-cost and easy-to-implement method. The carboxylic acid terminus of the GO molecule, which has a carboxylic acid terminus on its surface, was converted to acyl chloride (COCl-GO) through appropriate chemical reactions. In the second stage, in order to make graphene oxide A1 (COOH-GO) and A2 (COCl-GO) more stable, biocompatible, and functional in biological environments, they were surface modified with Bovine Serum Albumin (BSA), which is widely used in medical applications. A3 (BSA-COCl-GO) and A4 (BSA-COOH-GO), obtained as a result of GO modification with BSA, were analyzed by advanced characterization techniques such as FT-IR, FE-SEM, FESEM-EDS, XRD, and TEM. As a result of XRD analysis, the average crystal size of (BSA-COCl-GO)NP was determined to be 33.776 nm. In the third step, the synthesized BSA-COCl-GO nanoparticles were used in a fluorescence spectroscopy-based sensor system to determine protamine, a molecule widely used in surgical applications. The quantitative detection limit of the developed system was calculated as 380 ng/mL. It was also determined that the sensor performed optimally in the pH range of 7–10 and at temperatures of 293–303oK (20–30°C). When evaluated in terms of metal ion interactions, it was observed that the system was particularly affected by Fe²⁺, Fe³⁺, and Zn²⁺ ions. The reversibility of the sensor was tested using heparin, the antidote to protamine, demonstrating its suitability for multiple uses. The antimicrobial properties of the obtained nanostructures were also investigated. Tests on six different microorganisms revealed that GO and BSA-COCl-GO nanoparticles exhibited limited antibacterial and antifungal activity. In conclusion, this study demonstrated that BSA-modified GO nanoparticles can be effectively applied in the determination of protamine using fluorescence spectroscopy.