Fluorescence “Turn‐Off‐On” Detection of Heparin and Protamine Based on Bovine Serum Albumin‐Stabilized Carbon Dots (BSA‐CDs)

Abstract Heparin and protamine are two therapeutically significant biomolecules utilized in surgeries and extracorporeal therapy. Hence, real time monitoring of their concentration levels in body fluids is quite requisite. Herein, we developed, Bovine Serum Albumin stabilized carbon dots by a microwave‐assisted synthesis for the detection of heparin and protamine. Heparin has sulfate and carboxy groups that can interact with the positively charged surface amino groups of protamine through electrostatic interactions and hydrogen bonds. The blue fluorescence exhibited by BSA‐Carbon dots shows decrease in fluorescence emission on addition of negatively charged heparin. When cationic protein protamine is introduced to this system, the fluorescence is recovered due to electrostatic interaction with heparin. The system shows a Limit of detection (LOD) of 0.014 mM and 0.053 mM on addition of heparin and protamine respectively. The probe exhibited positive results with good selectivity and sensitivity towards other coexisting biomolecules and ions that appear in body fluids. The study was extended in biological matrix such as human serum and urine and found good recovery percentage in between 90–120%. The practical applicability was analyzed using a paper strip assay. Hence, a sensitive “turn‐off‐on” probe was effectively developed for the detection of heparin and protamine on a clinical basis.