Sensitive Detection of Formaldehyde Gas Using Modified Dandelion-Like SiO₂/Au Film and Surface Plasmon Resonance System.

To address the demands for the sensitive and real-time detection of formaldehyde gas at ambient temperature, a surface plasmon resonance (SPR) sensing system based on modified dandelion-like SiO₂ nanoparticles/Au thin film is developed. The sensing system relies on modified SiO₂ nanoparticles having radially arranged mesopores on the Au thin film, providing well-distributed and specific binding sites for formaldehyde and amplifying the sensing SPR signal. The linear range for the quantification is 0.2∼1.5 ppm with a limit of detection at 0.2 ppm. The regulation level of formaldehyde exposure suggests that the developed sensing system could be suitable to the real-time environmental and workplace monitoring.