Split-order flat-field lens grating microspectrometer for multiplex real-time PCR detection

A split-order flat-field lens grating microspectrometer (SOFLG-μSPEC) is presented for high-resolution, compact spectral analysis in multiplex qPCR. SOFLG-μSPEC module includes a microslit, collimating lens, transmission grating, concave mirror, flat-field lens, and dual long-pass filters. +1 and -1 diffraction orders pass through separate filters and converge on a CMOS linear sensor, with the flat-field lens correcting field curvature for a flat focal plane. SOFLG-μSPEC detects fluorescence signals from PCR dyes with high sensitivity. It allows successful singleplex quantification and simultaneous multiplex monitoring with spectral deconvolution. This compact design supports portable diagnostics and real-time genetic target analysis across diverse applications.