Electrochemical sandwich-type biosensors for α-1 antitrypsin with carbon nanotubes and alkaline phosphatase labeled antibody-silver nanoparticles.
A novel sandwich-type biosensor was developed for the electrochemical detection of α-1 antitrypsin (AAT, a recognized biomarker for Alzheimer's disease). The biosensor was composed of 3, 4, 9, 10-perylene tetracarboxylic acid/carbon nanotubes (PTCA-CNTs) as a sensing platform and alkaline phosphatase-labeled AAT antibody functionalized silver nanoparticles (ALP-AAT Ab-Ag NPs) as a signal enhancer. CNTs offer high surface area and good electrical conductivity. Importantly, Ag NPs could increase the amount of ALP on the sensing surface and the ALP could dephosphorylate 4-amino phenyl phosphate (APP) enzymatically to produce electroactive species 4-aminophenol (AP). For detecting AAT based on the sandwich-type biosensor, the results show that the peak current value of AP using ALP-AAT Ab-Ag NPs as signal enhancer is much higher than that by using ALP-AAT Ab bioconjugate (without Ag NPs), the biosensor exhibited desirable performance for AAT determination with a wide linearity in the range from 0.05 to 20.0pM and a low detection limit of 0.01pM. Finally, the developed sensor was successfully applied to the analysis of AAT concentration in serum samples.
Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Buk-gu, Daegu-city 41566, Republic of Korea; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: zhgb1030@ujs.edu.cn.
Gangbing
G
Zhu
Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, 80 Daehakro, Buk-gu, Daegu-city 41566, Republic of Korea. Electronic address: hyejinlee@knu.ac.kr.
Hye Jin
HJ
Lee
D000469:Alkaline Phosphatase / Q000737:chemistry; D000627:Aminophenols / Q000737:chemistry; D000906:Antibodies / Q000737:chemistry* / Q000276:immunology; D015374:Biosensing Techniques; D007118:Immunoassay; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*
D000627:Aminophenols; D000906:Antibodies; D037742:Nanotubes, Carbon; D000515:alpha 1-Antitrypsin; D012834:Silver; D000469:Alkaline Phosphatase; C026729:4-aminophenol
Alzheimer's disease; Antibody functionalized silver nanoparticles; Electrochemical biosensors; Sandwich assays; α−1 antitrypsin