Gold nanoparticle induced enhancement of molecular fluorescence for Zn2+ detection in aqueous niosome solution

Amit Nag, Shweta Pawar, Anupam Bhattacharya

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 Scopus citations

Abstract

Modified bipyridine-based construct 4-(pyridine-2-yl)-3H-pyrrolo [2,3-c] quinoline (PPQ), and its assemblies with niosomes and gold nanoparticles (GNP) to function as turn-on fluorescent sensors for biologically important Zn2+ in aqueous solution are evaluated. Earlier, we have shown fluorescence-based selective ratiometric detection of Zn2+ by PPQ in DMF [RSC Adv. 2014, 4, 25605]. This work attempts to overcome the water solubility problem of the hydrophobic PPQ, by using non-ionic surfactant led niosomes. The interest in niosome resides in the fact that they can mimic biological systems. Metals like Ag, Au are known to quench fluorescence, but using metal nanoparticles molecular fluorescence can be enhanced by increasing rate of excitation with concentrating electric field around the fluorophore and also by increasing the rate of radiative decay. This is known as Metal enhanced Fluorescence (MEF). When, PPQ binds with Zn2+ and forms the complex in presence of GNP, MEF is evident; whereas no significant fluorescence intensity enhancement is observed for PPQ in absence of either gold nanoparticles or Zn2+. The optimum size for the gold nanoparticles used in our study is ~40 nm, which shows the enhancement. The MEF is evident in niosomes, as there is an optimal distance between PPQ-Zn2+-PPQ complex (residing in the hydrophobic bilayer) and the nanoparticles (in the water pool). The enhancement in fluorescence intensity is accompanied by decrease in fluorescence lifetimes. The described sensing systems, are capable of detecting Zn2+ in HeLa cells at physiological conditions, as shown by bioimaging studies.

Original languageEnglish
Title of host publicationInternational Conference on Fibre Optics and Photonics, Photonics 2016
PublisherOptica Publishing Group (formerly OSA)
ISBN (Print)9781943580224
DOIs
StatePublished - 2016
Externally publishedYes
EventInternational Conference on Fibre Optics and Photonics, Photonics 2016 - Kanpur, India
Duration: 4 Dec 20168 Dec 2016

Publication series

NameOptics InfoBase Conference Papers
ISSN (Electronic)2162-2701

Conference

ConferenceInternational Conference on Fibre Optics and Photonics, Photonics 2016
Country/TerritoryIndia
CityKanpur
Period4/12/168/12/16

Bibliographical note

Publisher Copyright:
© OSA 2016.

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