Quantum dot-polymer nanocomposite for optical sensing

摘要

A quantum dot-polymer nanocomposite for optical chemical and biological sensing is formed by stably incorporating functionalized quantum dots into a pH sensitive hydrogel polymer network. At least one monomer of the pH sensitive hydrogel has functional groups selectively chosen to correspond to functionalized groups on the quantum dots to enable conjugation between the hydrogel polymer network and the functionalized quantum dots. The resulting quantum dot-polymer nanocomposite is placed in a solution having a known pH and addition of a chemical composition or biological agent of interest generates a change in pH of that solution. The nanocomposite expands or contracts responsive to the pH change. The pH change is optically detected by measuring the intensity level of fluorescence from the quantum dots when the nanocomposite is subjected to an excitation light source.

主权项

1. A quantum dot-polymer nanocomposite for optical sensing comprising: a plurality of quantum dots bound to a hydrogel polymer network formed from a mixture of a first monomer selected from the group consisting of acrylic acid (AA) and methacrylic acid (MAA) and an acrylate monomer using a cross-linking agent to form a pH responsive co-polymer, the quantum dot-polymer nanocomposite being in contact with a solution having an initial pH, wherein the addition of a biological or chemical contaminant generates a change in pH of the solution and thereby causes an expansion or contraction of the hydrogel polymer network, a light scattering effect of the polymer network and spacing between the plurality of quantum dots each change in correspondence to the expansion or contraction of the hydrogel polymer network and results in a change in a fluorescence emission intensity therefrom, wherein the change in pH is detected by measuring the change in quantum dot fluorescence emission intensity.