Determination of Bovine Serum Albumin Conjugated Drugs by Immobilization as Microarrays and Oblique-Incidence Reflectivity Difference Microscopy

Abstract

& Human serum is a mixture of various proteins which may interact with drugs. Therefore, it is of interest to investigate the binding kinetics of pharmaceuticals with their corresponding antibodies in serum. In this article, microarrays and a label-free biosensor were used to study these interactions. Microarrays provide a high-throughput platform for characterizing biomolecular interactions, and the label-free oblique-incidence reflectivity difference biosensor avoids the drawbacks of fluorescencebased methods. The experimental results show that the binding affinities between most of the drugs and their antibodies were reduced in human serum because the bulky proteins block the access to or reduce the stability of the reaction complexes. Therefore, one should be mindful when in vitro or in vivo testing the efficiency of potential drugs and their antibodies.

Real-time, label-free characterization of oligosaccharide-binding proteins using carbohydrate microarrays and an ellipsometry-based biosensor

“…The oblique-incidence reflectivity difference scanning microscope used in the present work was described in earlier publications [42, 51, 52]. It employed a He-Ne laser at a wavelength of 633 nm for illumination.…”

“…We recently developed the oblique-incidence reflectivity difference (OI-RD) microscopy for label-free detection of biomolecular interactions between solution-phase analyte and surface-immobilized microarrays [48–50]. This ellipsometry-based OI-RD microscope is suitable for both real-time measurements of binding curves and end-point imaging of biomolecular microarrays [51, 52].…”

Kinetic Analysis of Biomolecular Interactions Using Label-Free Biosensors

“…In a typical OI-RD experiment, signals from targets and their neighboring references are monitored, and the binding curves are derived by subtracting the average reference signal from the target signal. Considering the binding of surface-immobilized bovine serum albumin-conjugated phenobarbital to its solution-phased antibody as an example, [38] the raw binding curves containing signal drift and variation were very rough (data not shown). This phenomenon would affect data fitting.…”

“…Printing concentrations from 1 μM to 6 μM and probe concentrations of 0.001 mg/ml, 0.002 mg/ml, and 0.005 mg/ml were used sequentially. [38] The sensing surface was regenerated between two bindings to strip off captured probes.…”

Spatiotemporal Mapping of Extracellular Electron Transfer Flux in a Microbial Fuel Cell Using an Oblique Incident Reflectivity Difference Technique

“…OIRD is a newly established optical technique susceptible to the interfacial dielectric constant and surface properties (see its principle and setup in Figure S1 in the Supporting Information) . It has demonstrated intriguing ability for real-time and label-free monitoring of various surface/interface processes. − PANI is one of the most used conducting polymers in MFCs due to its good biocompatibility and conductivity. , PANI can be reversibly oxidized and reduced with simultaneous ion doping/de-doping, leading to its dielectric constant change to arouse the OIRD signal, as demonstrated in previous work. − In the present work, as in Scheme , a model bioanode was constructed by inhabiting Shewanella putrefaciens CN32, a robust exoelectrogenic bacterium, on the PANI nanowire film-coated fluorine-doped tin oxide (FTO) electrode (denoted bacteria-PANI-FTO) . In the open-circuit state, the PANI film was reduced by the inhabited cells via EET, and its redox state and dielectric constant change were monitored by OIRD to enable spatiotemporal mapping of the EET flow.…”