An electrochemical immunosensor for aflatoxin M1 determination in milk using screen-printed electrodes.
Biosens Bioelectron
; 21(4): 588-96, 2005 Oct 15.
Article
in En
| MEDLINE
| ID: mdl-16202872
ABSTRACT
The production and assembling of disposable electrochemical AFM1 immunosensors, which can combine the high selectivity of immunoanalysis with the ease of the electrochemical probes, has been carried out. Firstly immunoassay parameters such as amounts of antibody and labelled antigen, buffer and pH, length of time and temperature of each steps (precoating, coating, binding and competition steps) were evaluated and optimised in order to set up a spectrophotometric enzyme-linked immunosorbent assay (ELISA) procedure. This assay exhibited a working range between 30 and 160 ppt in a direct competitive format. Then electrochemical immunosensors were fabricated by immobilising the antibodies directly on the surface of screen-printed electrodes (SPEs), and allowing the competition to occur between free AFM1 and that conjugated with peroxidase (HRP) enzyme. The electrochemical technique chosen was the chronoamperometry, performed at -100 mV. Furthermore, studies of interference and matrix effects have been performed to evaluate the suitability of the developed immunosensors for the analysis of aflatoxin M1 directly in milk. Results have shown that using screen-printed electrodes aflatoxin M1 can be measured with a detection limit of 25 ppt and with a working range between 30 and 160 ppt. A comparison between the spectrophotometric and electrochemical procedure showed that a better detection limit and shorter analysis time could be achieved using electrochemical detection.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Immunoassay
/
Food Contamination
/
Aflatoxin M1
/
Milk
/
Electrochemistry
/
Electrodes
/
Food Analysis
Type of study:
Diagnostic_studies
/
Evaluation_studies
Limits:
Animals
Language:
En
Journal:
Biosens Bioelectron
Journal subject:
BIOTECNOLOGIA
Year:
2005
Document type:
Article
Affiliation country:
Italy
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM