An electrochemical peptide-based Ara h 2 antibody sensor fabricated on a nickel(II)-nitriloacetic acid self-assembled monolayer using a His-tagged peptide.
We report, for the first time, the use of a Ni(II)-nitriloacetic acid (NTA) self-assembled monolayer (SAM) in the fabrication of an electrochemical peptide-based (E-PB) sensor for detection of anti-Ara h 2 antibodies. We compared the performance of the sensor fabricated on a Ni(II)-NTA SAM using a His-tagged peptide with the sensor fabricated using the conventional approach via direct immobilization of a thiolated peptide. While both sensors responded only to the correct antibody in the presence of random antibodies, we observed differences between the sensors. Specifically, the detection limit of the His-tagged sensor was 1pM, significantly lower than the 200pM detection limit of the conventional thiolated sensor. More importantly, unlike our previously developed E-PB sensors, both sensors are regenerable and reusable. The thiolated sensor can be readily regenerated using guanidine hydrochloride; whereas the His-tagged sensor can be regenerated by direct displacement of the His-tagged probes using Ni(II) ions. Overall, our results show that both approaches are well-suited for E-PB sensor fabrication; more importantly, specific sensor properties such as detection limit and dynamic range can be tuned by simply using a different probe immobilization method.
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA.
Anita J
AJ
Zaitouna
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA. Electronic address: rlai2@unl.edu.
Rebecca Y
RY
Lai
D000906:Antibodies / Q000032:analysis*; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D006639:Histidine / Q000032:analysis / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D009571:Nitrilotriacetic Acid / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*
D000906:Antibodies; D009942:Organometallic Compounds; D010455:Peptides; D006639:Histidine; D009532:Nickel; D009571:Nitrilotriacetic Acid
Alternating current voltammetry; Antibodies; Ara h 2; Electrochemical peptide-based sensor; Methylene blue; Peanut allergy