© 2019 IEEE. We proposed an identification system of amplified target ribonucleic acids (RNAs) without optical filters using a filter-free multiple wavelengths sensor. To detect fluorescence from transcription reverse transcription concerted reaction (TRC) combined with intercalation activating fluorescence probe (INAF), a compact system fabricated with optimized physical parameters of light source and sensor. The excitation light and fluorescence from reagent were successfully separated using the proposed parameters based on controlled the intensity of the excitation light and the potential depth of the sensor. We succeeded in identifying each target RNAs in less than 10 minutes without using an optical filter. The Filter-free multiple wavelengths sensor can be applied in the application of biotechnology and help to realize miniaturized bio-devices.