An HRP-integrated CRISPR/Cas12a biosensor towards chair-side diagnosis for Porphyromonas gingivalis.

Rapid diagnostic tools for Porphyromonas gingivalis (Pg), the primary microorganism responsible for the development of periodontitis, particularly those designed for chair-side applications, could provide substantial health benefits to patients. To address this issue, we developed a CRISPR/Cas12a-based rapid Pg detection method. Dual-gRNA and hairpin reporter strategies were employed to enhance CRISPR/Cas12a reaction efficiency. By modifying the hairpin reporter with HRP, the pre-amplification-free HRP-CRISPR/Cas12a reaction was enabled to produce a colorimetric output, amplifying the detection signal. This method achieved high sensitivity (as low as 33 CFU) without the risk of aerosol contamination from pre-amplification. When testing clinical samples, the method showed high consistency with the reference RT-PCR. Furthermore, compared with RT-PCR, this method only requires room temperature operation, is simpler, and has a shorter detection time of about 35 min. In conclusion, the pre-amplification-free HRP-integrated CRISPR/Cas12a detection method requires no complex equipment, making it an ideal, end-user-friendly approach for chair-side Pg detection.