Skip to Content
MilliporeSigma
  • A quantum dot based electrochemiluminescent immunosensor for the detection of pg level phenylethanolamine A using gold nanoparticles as substrates and electron transfer accelerators.

A quantum dot based electrochemiluminescent immunosensor for the detection of pg level phenylethanolamine A using gold nanoparticles as substrates and electron transfer accelerators.

The Analyst (2014-07-12)
Panpan Yan, Jing Zhang, Qinghui Tang, Anping Deng, Jianguo Li
ABSTRACT

This study reports the development of an electrochemiluminescent (ECL) immunosensor for ultrasensitive detection of phenylethanolamine A (PA) based on CdSe quantum dots (QDs) and gold nanoparticles (GNPs). The GNPs/ovalbumin-PA/anti-PA-QD immunosensor was fabricated layer by layer using GNPs as substrates and electron transport accelerators. The use of GNPs greatly enhanced the sensitivity for detecting PA due to the excellent electron transportation ability and the large surface area of GNP carriers allowing several binding events of ovalbumin-PA on each nanosphere. Transmission electron microscopy images (TEM), photoluminescence spectra, ultraviolet-visible absorption spectra and dynamic light scattering (DLS) were used to characterize the QDs and GNPs. The sensor was characterized with electrochemical impedance spectra (EIS), and a strong ECL emission of the modified electrode could be observed during the cathodic process of S2O8(2-) and QDs in air-saturated PBS buffer containing 0.1 M K2S2O8 and 0.1 M KCl (pH 7.4). With a competitive immunoassay format, the ECL signal depended linearly on the logarithm of the phenylethanolamine A concentration within a range of 0.02 ng mL(-1) to 50 ng mL(-1), and the detection limit was 0.0047 ng mL(-1), much lower than those reported in the literature. This ECL immunosensor is rapid, simple and sensitive with acceptable precision, and it will extend the application of QD ECL in immunoassays of β-agonists and open new avenues for the detection of food additive residues in the future.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Potassium peroxodisulfate, puriss. p.a., ACS reagent, ≥99.0% (RT)
Sigma-Aldrich
Sodium borohydride solution, 2.0 M in triethylene glycol dimethyl ether
Supelco
Potassium chloride solution, conductance standard B acc. to ISO 7888, 0.01 M KCl
Supelco
Potassium chloride solution, conductance standard A acc. to ISO 7888, 0.1 M KCl
Supelco
Potassium chloride solution, conductance standard C acc. to ISO 7888, 0.001 M KCl
Sigma-Aldrich
Sodium phosphate dibasic solution, BioUltra, 0.5 M in H2O
Sigma-Aldrich
VenPure® SF, powder
Sigma-Aldrich
Potassium chloride, tested according to Ph. Eur.
Supelco
Potassium chloride solution, for Ag/AgCl electrodes, ~3 M KCl, saturated with silver chloride
Sigma-Aldrich
Thioglycolic acid, ≥99%
Sigma-Aldrich
Thioglycolic acid, 98%
Supelco
Phosphate Standard for IC, TraceCERT®, 1000 mg/L phosphate in water (nominal concentration)
Supelco
Potassium chloride solution, BioUltra, ~3 M in H2O
Supelco
ISA (ionic strength adjustment solution: 1 M KCl), 1 M KCl
Supelco
Potassium Chloride, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Potassium chloride, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, ≥99.0%
Sigma-Aldrich
Isopropyl alcohol, ≥99.7%, FCC, FG
Sigma-Aldrich
Citrate Concentrated Solution, BioUltra, for molecular biology, 1 M in H2O
Sigma-Aldrich
Potassium chloride, for molecular biology, ≥99.0%
Sigma-Aldrich
Potassium chloride, AnhydroBeads, −10 mesh, 99.99% trace metals basis
Supelco
Sodium Citrate, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Potassium chloride solution, 0.075 M, sterile-filtered, BioXtra, suitable for cell culture
Sigma-Aldrich
Citrate Concentrated Solution, BioReagent, suitable for coagulation assays, 4 % (w/v)
Sigma-Aldrich
Potassium chloride, BioUltra, for molecular biology, ≥99.5% (AT)
Sigma-Aldrich
Potassium chloride solution, 0.01 M
Sigma-Aldrich
Potassium chloride, 99.999% trace metals basis
Sigma-Aldrich
Potassium chloride, ≥99.99% trace metals basis
Sigma-Aldrich
Potassium chloride, AnhydroBeads, −10 mesh, 99.999% trace metals basis
Sigma-Aldrich
Potassium chloride solution, BioUltra, for molecular biology, ~1 M in H2O
Sigma-Aldrich
Potassium chloride, BioXtra, ≥99.0%