Finite Element Design of Biomolecular Sensor Chip Based on QCM/LSPR Dual Technology

Biomolecular sensor chips can realize real-time monitoring of biomolecular mass, promote the research and development of biomolecules, and have important research value.In this paper, a dual technology sensing detection method combining QCM/LSPR is proposed. Through the simulation analysis of the finite element analysis software COMSOL Multiphysics, the reasonable structure and parameters of the chip are obtained.It was found that the arrangement structure of gold nanorod dimer greatly affected the LSPR of nanorods, and then affected the detection results of biomolecules.Compared with the parallel arrangement of gold nanorods, the resonance peak value of longitudinal arrangement is larger, and the electromagnetic field acts more directly on the space near the connection point, which can enhance the local electric field strength.In addition, in terms of chip oscillation performance, the simulation found that the series capacitor between the oscillator and the voltage source will increase the resonant frequency. Different series capacitors correspond to different resonant frequencies. The resonant frequencies at different points of the same chip are basically the same but the amplitudes are different. On this basis, through simulation analysis of QCM mass sensitivity distribution, it is concluded that compared with the polar structure, the non-polar structure used to assemble the gold nanorod has a higher particle displacement amplitude in the central area of the ring gold electrode, and the mass sensitivity is doubled, which is conducive to the improvement of the plasma resonance characteristics of the gold nanorod. We integrate chips of two technologies, complement each other's advantages, overcome the lack of detection of a single technology, and have broad prospects in biomolecular research.