Molecular sieve redefines SPR sensible range for “win-win” dual functions to enhance the sensitization and anti-fouling

Abstract

The precise measurement of trace levels of small molecules in complex environments faces great challenges. The inherent limitation of the limited sensible range of surface plasmon resonance (SPR) is ingeniously leveraged in this work. Zeolite imidazolate frameworks-8 (ZIF8) as a sieve-induced antifouling layer, with gold nanobipyramids (AuNBPs) encapsulated within ZIF8 serving as the sensitizing material for simultaneous antifouling and sensitization. The electromagnetic field at the interface is modeled and simulated using the finite-difference time-domain (FDTD) method to ensure the proper match between the perceptible range and the shell layer thickness. The kinetic size of the molecules is calculated using multifunctional wavefunction analysis to ensure the pore size of ZIF8 is matched to the size of the target substance. The Grand Canonical Monte Carlo (GCMC) method simulated the adsorption of molecules with different properties in ZIF8, ensuring that the target molecule would pass through the pores into the effective sensing range, while impurities would be sieved out for sensitive and specific detection. This theoretical simulation and experimental design strategy, based on AuNBPs@ZIF8-modified integrated sensors, shows significant potential for application.