A novel interdigitated capacitor based biosensor for detection of cardiovascular risk marker

Label-free capacitive biosensor for sensitive detection of multiple biomarkers using gold interdigitated capacitor arrays

“…The free carboxyl groups of MPA on the surface of GID electrodes of capacitor arrays were activated by incubating with a mixture of 0.05 M of EDC and 0.03 M of NHS in distilled water for 5 h. The surface activated GIDcapacitors arrays were then divided into two groups for formats I and II, respectively. In format I, each activated GID electrode array was covalently coupled with specific pure form of 20 l of 100 g/ml antibodies (anti-CRP, -TNF␣, -IL6), respectively in PBS for 1 h at room temperature (Quershi et al, 2009). Where as in format II, the anti-CRP, -TNF␣, and -IL6 antibodies were mixed in the ratio of 1:1:1 and co-immobilized covalently on activated GID electrodes by incubating 20 l of 100 g/ml of the antibody mixture.…”

“…Thus, when there is a change in the dielectric properties of the material between the electrodes, a change in the capacitance will occur and it is correlated to the bound antigen molecules and amount captured by antibodies on the surface, as well as between the electrodes. There have been some reports on label-free capacitive biosensors with or without redox mediator (faradaic or non-faradaic) (Carrara et al, 2009;de Vasconcelos et al, 2009;Quershi et al, 2009;Saravan et al, 2008;Zor et al, 2009). It is observed that the capacitance behavior of most sensors often are prone to large standard deviation, poor reproducibility from electrode to electrode, non-specific signal and the interface behavior is not uniform as that of an ideal capacitor.…”

“…The fact that the present study is different from the previous reports in several important considerations. These include (a) efficient covalent immobilization of pure/mixture of antibodies directly on an optimized GID electrode geometry compared to epoxy-silanization (Saravan et al, 2008), which is prone to less sensitivity, and (b) use of a less-expensive SiO 2 background of the capacitors with high sensitivity compared to that reported with nanocrystalline diamond (NCD) background (Quershi et al, 2009). We here, investigated a simple, label-free, and sensitive multianalyte capacitive immunoassay that can be potentially applied for developing handheld devices for point-of-care applications.…”

Properties of LTCC Dielectric Tape in High Temperature and Water Environment

“…Design of IDC IDC is a periodic electrode structure, of totally N fingers, where each finger has width w, finger length l, adjacent finger spacing s, finger thickness t with total area of (d x x d y ) mm 2 , and LTCC substrate of h thickness. Layout of the designed IDC electrode and 3D models of sensors are presented in Fig.…”

Biosensors for Cancer Biomarkers

“…Recently, the label was developed the redox mediator used in capacitive biosensors in this system (Carrara et al, 2009;de Vasconcelos et al, 2009;Saravan et al, 2008). In this study, the covalent bonding on an optimized GID is connected antibodies via epoxy-silanisation (Saravan et al 2008), this method is less prone to sensitivity, the other less cheap silicon dioxide with a high-sensitive measurement applied to nanocrystalline diamonds (Quershi et al , 2009). GID arrays of silicon oxide surface with a thick layer of tungsten, first a thin gold layer is coated in advance to allow for the creation of an easier way.…”