Bio-inspired temporal regulation of ion-transport in nanochannels.

K P Sonu,Muthusamy Eswaramoorthy,Shikha Dhiman,Sushmitha Vinikumar,Subi J George

doi:10.1039/c8na00414e

K P Sonu, Muthusamy Eswaramoorthy + Show 3 more

Open Access

https://doi.org/10.1039/c8na00414e

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Abstract

Temporal regulation of mass transport across the membrane is a vital feature of biological systems. Such regulatory mechanisms rely on complex biochemical reaction networks, often operating far from equilibrium. Herein, we demonstrate biochemical reaction mediated temporal regulation of mass transport in nanochannels of mesoporous silica sphere. The rationally designed nanochannels with pH responsive electrostatic gating are fabricated through a hetero-functionalization approach utilizing propylamine and carboxylic acid moieties. At basic pH, cationic small molecules can diffuse into the nanochannels which release back to the solution at acidic pH. The transient ion transport is temporally controlled using a base as fuel along with esterase enzyme as the mediator. The slow enzymatic hydrolysis of a dormant deactivator (ethyl acetate) determines the lifetime of transient encapsulated state, which can be programmed easily by modulating the enzymatic activity of esterase. This system represents a unique approach to create autonomous artificial cellular models.

Highlights

Biological systems have been a long standing inspiration for temporal control over self-assembled nanostructures and functions
Injection of chemical fuel along with dormant deactivator reverses the surface charge of the compartments, which leads to the uptake of the CV+
The transient ion transport can be temporally programmed by variation of concentration of the chemical components

Summary

Introduction

Biological systems have been a long standing inspiration for temporal control over self-assembled nanostructures and functions. The transient ion transport is temporally controlled using a base as fuel along with esterase enzyme as the mediator. Scheme 1 Bio-inspired enzyme regulated temporal regulation of ion transport in nanochannels: the pH responsive charge reversal in mesoporous silica nanochannels (MCM-Z) is integrated with a nonlinear pH modulating enzymatic reaction – ethyl acetate (dormant deactivator, DD) hydrolysis by esterase.

Results

Conclusion