Rapid indirect detection of N-lactoyl-phenylalanine using dual DNA biosensors based on solution-gated graphene field-effect transistor

As obesity rates continue to rise, there is an increasing focus on reducing obesity through exercise. People are becoming more aware of the importance of weight loss through physical activity. However, the effectiveness of exercise can vary significantly among individuals, making it challenging to evaluate its impact. Therefore, establishing a reliable method for assessing exercise effectiveness is crucial for enhancing exercise quality and reducing obesity risk. It is noteworthy that the relationship between N-lactoyl-phenylalanine (N-Lac-Phe) and energy metabolism has garnered considerable attention. In this study, we developed a N-Lac-Phe biosensor by detecting L-lactic acid (L-Lac) and L-phenylalanine (L-Phe) based on Solution-Gated Graphene Field-Effect Transistors (SGGT). Our findings showed that the L-Lac and L-Phe biosensors exhibited excellent linearity within concentration ranges of 300 pM to 300 nM for L-Lac and 3 nM–1000 nM for L-Phe, with R² values of 0.9934 and 0.9897, respectively. The detection accuracies for these two types of SGGT biosensors were 91.63 ± 6.97% and 99.39 ± 8.53%, respectively. Using the established N-Lac-Phe, L-Lac, and L-Phe relationship model (NLL model), we could calculate the concentration of N-Lac-Phe in the RAW264.7 culture medium based on the concentrations of L-Lac and L-Phe. The biosensors demonstrated excellent accuracy and selectivity, indicating their potential for rapidly evaluating the effectiveness of exercise.