Borophene Quantum Dots with Enhanced Nanozymatic Activity for the Detection of H₂O₂ and Cardiac Biomarkers

Quantum dots with unconventional properties can bring massive opportunities in multidirectional applications. Herein, borophene quantum dots (BQDs) have been synthesized that exhibit nanozymatic activity in addition to their conventional fluorescence emission nature and antibacterial activity. Fluorescence emission peak position and decay time were 450 nm and 2.8 ns, respectively. The average size of the BQDs was 5.2 nm. A significant 5-fold enhancement of the nanozymatic activity of BQDs was observed through an electrochemical process that enabled H₂O₂ detection with an exceptional limit of detection (LOD) value of 3.5 nM. A mechanism study revealed that two factors, for example, radical scavenging and electroassisted oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) have played significant roles in enhancing detection sensitivity and reducing detection time. BQDs possessed over 80% radical scavenging ability and, under an electrochemical field, demonstrated a 50-fold increase in the oxidation reaction of TMB compared with the conventional method. These remarkable findings were further utilized for the quantification of cholesterol and choline in a simulated blood sample with LOD values of 0.13 and 0.38 μM, respectively. The groundbreaking results presented in this study have the potential to open a pathway to move from the conventional nanozymatic detection method to an electroassisted one in the future.