Accelerating the design of gold/polymers/silica-based imprinted nanocomposite for light-triggered recognition and separation of biomolecules

Development of nanocomposites with environmentally response-type affinity sites, which can rapidly change the recognition rates in response to external, noninvasive stimuli, has broad technological applications for areas. In this work, inspired by a polydopamine (pDA) self-assembly strategy, a well-defined optically and thermally responsive silica/MIPs/gold nanocomposite (TO-MIPs) was successfully synthesized for the selective recognition and separation of sodium cholate hydrate (SCH). The design and engineering of these smart materials was achieved through the coupling of pDA-modified SiO₂ surfaces with poly(N-isopropyl acrylamide) (PNIPAm)-based SCH-imprinted layers that can change their physical conformation in response to heat. The TO-MIPs were finally synthesized by being coupled with Au nanoparticles (the sensitive light-heat converter) through an in situ reduction of metallic salts. Importantly, largely enhanced rebinding capacity (37.87 mg/g) and regeneration performance were both achieved. Moreover, with the opto-thermally responsive ‘specific recognition sites’, the as-prepared TO-MIPs not only exhibited rapid specific adsorption dynamics, but also possessed opto-thermally responsive separation performance of SCH. This biologically inspired methodology processed high durability and regeneration performance and was capable of reversibly controlling specific binding capacities of SCH from 11.76 to 35.79 mg/g in less than 5 min using the noninvasive stimulus of light. Additionally, the whole synthesis procedures were conducted in aqueous solution at low temperature, which are environmental friendly for scaling up without pollution.