A temperature-resistant ultrasensitive fluorescence aptasensor for the As(III) detection in aquatic products

An aptamer-imprinted polymer was synthesized as an As(III) aptasensor for the first time by stabilizing the recognition conformation of the aptamer. Chlorophyll-modified carbon quantum dots were doped into the polymer with fluorescence enhancement to As(III), thereby developing an efficient "turn-on" aptasensor.

The interactions between the aptamer and functional monomer with As(III) were analyzed using molecular docking and molecular dynamics simulations. The results showed that both were hydrogen bonds, but there was a significant difference in their binding energies. Therefore, this aptasensor exhibited a two-stage linear response to As(III) over a broad range of 0.9 nM-500 nM, with an LOD of 0.89 nM. And the detection time is only 10 min. Compared to the traditional aptamer biosensor without imprinting, the proposed aptasensor's limited spatial domain effectively minimized interference from environmental temperature fluctuations, thereby ensuring the detection stability within the range of 20 °C-60 °C. Furthermore, its specificity for the target detection was significantly improved in comparison to the traditional imprinted polymer without aptamer. Enzymatic hydrolysis was employed as the pretreatment method for the aquatic samples. By integrating with aptasensor, a practical method with an excellent accuracy ranging from 86.34 % to 105.59 % for As(III) detection in aquatic products was also developed.

This study contributes to the development of synergistic recognition and detection technologies based on multiple molecular recognition elements.