TY - JOUR
T1 - Electrochemical detection of Salmonella using gold nanoparticles
AU - Afonso, André S.
AU - Pérez-López, Briza
AU - Faria, Ronaldo C.
AU - Mattoso, Luiz H.C.
AU - Hernández-Herrero, Manuela
AU - Roig-Sagués, Artur Xavier
AU - Maltez-da Costa, Marisa
AU - Merkoçi, Arben
PY - 2013/2/15
Y1 - 2013/2/15
N2 - A disposable immunosensor for Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S) detection using a magneto-immunoassay and gold nanoparticles (AuNPs) as label for electrochemical detection is developed. The immunosensor is based on the use of a screen-printed carbon electrode (SPCE) that incorporates a permanent magnet underneath. Salmonella containing samples (i.e. skimmed milk) have been tested by using anti-Salmonella magnetic beads (MBs-pSAb) as capture phase and sandwiching afterwards with AuNPs modified antibodies (sSAb-AuNPs) detected using differential pulse voltammetry (DPV). A detection limit of 143 cellsmL-1 and a linear range from 103 to 106 cellsmL-1 of Salmonella was obtained, with a coefficient of variation of about 2.4%. Recoveries of the sensor by spiking skimmed milk with different quantities of Salmonella of about 83% and 94% for 1.5×103 and 1.5×105 cellsmL-1 were obtained, respectively. This AuNPs detection technology combined with magnetic field application reports a limit of detection lower than the conventional commercial method carried out for comparison purposes in skimmed milk samples. © 2012 Elsevier B.V.
AB - A disposable immunosensor for Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S) detection using a magneto-immunoassay and gold nanoparticles (AuNPs) as label for electrochemical detection is developed. The immunosensor is based on the use of a screen-printed carbon electrode (SPCE) that incorporates a permanent magnet underneath. Salmonella containing samples (i.e. skimmed milk) have been tested by using anti-Salmonella magnetic beads (MBs-pSAb) as capture phase and sandwiching afterwards with AuNPs modified antibodies (sSAb-AuNPs) detected using differential pulse voltammetry (DPV). A detection limit of 143 cellsmL-1 and a linear range from 103 to 106 cellsmL-1 of Salmonella was obtained, with a coefficient of variation of about 2.4%. Recoveries of the sensor by spiking skimmed milk with different quantities of Salmonella of about 83% and 94% for 1.5×103 and 1.5×105 cellsmL-1 were obtained, respectively. This AuNPs detection technology combined with magnetic field application reports a limit of detection lower than the conventional commercial method carried out for comparison purposes in skimmed milk samples. © 2012 Elsevier B.V.
KW - Electrochemical detection
KW - Gold nanoparticles
KW - Label
KW - Magneto-immunoassay
KW - Salmonella
U2 - 10.1016/j.bios.2012.06.054
DO - 10.1016/j.bios.2012.06.054
M3 - Article
SN - 0956-5663
VL - 40
SP - 121
EP - 126
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
ER -