Dual-channel fiber-optic biosensors based on LSPR and SPR for the trace detection of rabies virus

In this paper, a transmissive dual-channel fiber-optic biosensor based on local surface plasmon resonance (LSPR) and surface plasmon resonance (SPR) is designed for the simultaneous detection of rabies virus antibody and temperature. In the traditional dual-channel SPR sensor structure, it is necessary to coat different metal films on two channels to obtain two independent SPR signals in one probe. In this work, the dopamine hydrochloride was used to separate two resonance peaks. Sensing channel 1 is used as an immunosensing road by using the LSPR effect, coating its surface with gold nanoparticles (AuNPs)/IRMOF-3/thiomalic acid and adsorbing rabies virus antigens to enhance the loading of biomolecules on the surface of the sensor and the immune response. The sensing channel 2 adopts a silver film to excite the SPR effect, then the position of the SPR resonance peak is shifted back by dopamine hydrochloride, and, finally, a layer of polydimethylsiloxane is coated as a temperature sensing channel. The results show that the sensitivity of the sensor is 0.504 nm/°C in the temperature range of 30–35 °C, and it has good temperature stability. The high sensitivity detection of rabies virus was achieved in the range of 0.1–103 pg/ml. The sensitivity and detection limit are 3.065 nm/(log(pg/ml)) and 0.234 pg/ml, respectively. It performed well in the clinical sample detection. The sensor has a good prospect in the clinical detection of rabies virus.