Gold Electrode Modification with Thiolated Hapten for the Design of Amperometric and Piezoelectric Immunosensors

Abstract

Self-assembly of a hapten monolayer is used for the development of amperometric and piezoelectric immunosensors. A disul®de compound carrying a terminal pyrene group was newly synthesized for the modi®cation of a gold surface. The self-assembled organic monolayer was formed spontaneously through the use of a disul®de head group. The resulting monolayer and its long-term stability on a gold surface were measured by cyclic voltammetry. The application of the hapten monolayer to amperometric and piezoelectric immunosensing of monoclonal antibodies and benazo[a]pyrene (BaP) was also investigated.

Development of redox-labeled electrochemical immunoassay for polycyclic aromatic hydrocarbons with controlled surface modification and catalytic voltammetric detection

“…ECIA has attracted great attention for the on-site screening of environmental pollutants due to its advantages of short response time, low-cost, small size and adequate sensitivity (Liu et al, 1998(Liu et al, , 2000Fahnrich et al, 2003;Moore et al, 2004;Badihi-Mossberg et al, 2007;Lin et al, 2007). In particular, miniaturization of electrochemical devices can be achieved by employing well-established microelectronics fabrication techniques.…”

“…Benzo[a]pyrene (BaP) is considered as one of the most carcinogenic PAHs, and has thus generated considerable interest in the rapid and sensitive detection of this pollutant by immunoassays including ECIA (Liu et al, 1998(Liu et al, , 2000. Detection of BaP was also attempted in our work.…”

“…BaP at the highest tested concentration (10 M) leads to a loss of signal by approximately fifty eight percent. The detection limit (S/B = 3) is estimated to be 10 nM (equal to 2.4 ng mL −1 ), which is 10-fold lower than the result obtained in a previous work by competitive inhibition voltammetric immunoassay (Liu et al, 2000), and is as sensitive as the enzyme-labeled amperometric immunoassay for phenanthrene (Fahnrich et al, 2003). The detection limit for BaP varies in other established immunoassays.…”

Engineered Antibodies for Monitoring of Polynuclear Aromatic Hydrocarbons

“…Binding of BaP-6a-BSA and pyrene-1a-BSA conjugates at concentrations of 0.01-6.0 µM was detected by linear sweep voltammetry, as a decrease in the charging current. 60,61 A piezoelectric flow-through immunosensor was also constructed.…”

“…This sensor could be used to detect 10C10 antibody, and soluble BaP, pyrene and naphthalene. 61,62 These experiments demonstrated the potential for incorporating these antibodies in practical PAH sensor devices.…”