Development of ultra-sensitive and selective nanoparticle-based biosensors

Abstract

This thesis depicts research efforts aimed at developing novel biosensors based on oligonucleotide, small molecules or enzymes functionalized metal nanoparticles, for sensitive and selective detection of metal ions, DNA, small organic molecules and enzymes. In chapter 2, a useful sensor system consisted of EcoRI-modified gold nanoparticle and DNA sticky end pairing is clarified for colorimetric detection of magnesium ions (Mg2+) and pyrophosphate ions (PPi) in aqueous solution.. In chapter 3, a chip-based platform using oligonucleotide-modified gold nanoparticles, to determine the effectivity of commercial sunscreen against UV light is investigated.. In chapter 4, a real-time colorimetric method, based on mercaptoundecanoic acid (MUA)-modified nanoparticles, cupric ion and the enzyme?s natural substrate PPi, to detect the activity of alkaline phosphatase is presented. In chapter 5, on the basis of upconverted luminescence resonance energy transfer, a platform for screening of cobalt ions in the presence of ethylenediamine in aqueous solutions using acid-capped NaYF4:Yb,Tm@NaYF4 core-shell upconversion nanoparticles is developed.