Photo modulated Fluidic Channels for Precise Delivery of Ions and Molecules

Abstract

Fabrication of remote-controlled ion and molecule delivery devices with sub-nanomolar accuracy possesses enormous potential of application in futuristic areas like bio-sensing, molecular machines, energy storage/harvesting, separation, and purification. Here, we combined the excellent photothermal characteristics of oxidised multiwalled carbon nanotubes (o-CNT) with atomically thin 2D sheets of V2O5 (VO) to fabricate fluidic devices capable of discharging ions and molecules with sub-nanomolar accuracy. Remarkably, the delivery of ionic/molecular pulses can be remotely modulated through irradiation of IR light. The heterostructure fluidic membrane (HFM), fabricated as a bilayer membrane with distinctive regions of o-CNT and VO, can continuously deliver K+ ions at the rate of ~ 0.58 nmol/min. The ionic flow rate can be further tuned by modulating the thickness and composition of the HFM. Moreover, triangular HMF can discharge ions in nanomolar pluses (~ 1.85 to 6.92 nmol/pulse) remotely triggered through light of different intensities. Likewise, the intermixed fluidic membrane (IFM), fabricated through vacuum filtration of the homogeneous mixtures of the VO and o-CNT, can discharge biologically relevant molecules like tryptophan (Trp) and aspirin at a rate as low as 0.1 nmol/min, which can be further modulated with light and heat.