Boron nitride nanotube-based creatinine biosensors for athlete physical condition monitoring

Abstract

Monitoring creatinine levels is critical for evaluating renal function and muscular health in athletes. Creatinine is a waste product of creatine metabolism in skeletal muscle, and is filtered by the kidneys at a relatively constant rate. Elevated serum creatinine can indicate impaired kidney function, rhabdomyolysis, or skeletal muscle trauma. In athletes, creatinine levels increase after intense exertion due to muscle breakdown and myoglobin release. Abnormal creatinine signifies poor training adaptation, overtraining, or trauma. Therefore, close monitoring of creatinine in athletes provides insight into their physical condition. Current laboratory methods for measuring creatinine like Jaffe reaction and high-performance liquid chromatography are accurate but time-consuming, requiring blood sampling. Biosensors offer rapid, painless creatinine detection from small volumes, but current versions suffer from instability, use of mediators, and lack portability. Boron nitride nanotubes (BNNTs) are promising materials for electrochemical biosensing due to their structure, surface chemistry, and biocompatibility. Here, we report BNNT-based electrochemical biosensors for detecting creatinine in blood samples from athletes. BNNTs synthesized by induction thermal plasma technique were used to immobilize creatinine metabolizing enzymes. Creatinine levels were measured by chronoamperometry and compared to isotope dilution mass spectrometry. We demonstrate high sensitivity and selectivity of the BNNT biosensor with facile fabrication method and portable platform, promising for rapid creatinine monitoring in athletes. This can provide insight into muscular damage and renal function during training and competition.