Fig. 7

Three biosensors (DNA-engineered nanozymes) are used to detect S. mutans in saliva samples. Out of the three nanosystems, the one constructed with affinity-coupling and DNAzyme included showed the best specificity and the greatest sensitivity. A nanosystem like that has several built-in advantages. The DNA aptamer's role as a molecular recognition element and target sticky material results in the suppression of bacterial enzymatic activity. The identified process was then completed in 15 min, saving hours of molecular extraction or days of traditional culturing time. It was an easy and quick process. The colorimetric signal response of all three biosensors showed a concentration-dependent pattern, wherein the absorbance gradually decreased as the S. mutans concentration rose [131]