Surface functionalization chemistries on highly sensitive silica-based sensor chips

Abstract

The surfaces of silica-based sensor chips, designed for evanescent-field-coupled waveguide-mode sensors, were functionalized using various surface chemistries. The immobilization of molecular entities on the functionalized silica surfaces was monitored using various microscopic techniques (scanning electron, fluorescence, and atomic force microscopies). Further, gold nanoparticle-based signal enhancement analyses were performed with protein conjugation on different functionalized surfaces using a waveguide-mode sensor. Based on these analyses, the sensor surfaces modified with glutaraldehyde (Glu) and carbonyldiimidazole were found to be good for molecules of different sizes. In addition, it can be inferred that the Glu-modified surface may be suitable for small molecules with diameters around 5 nm owing to its surface roughness. The modified surface with carbonyldiimidazole is suitable for the direct immobilization of larger molecules especially for biomolecular assemblies without intermediate chemical modifications.

Investigation on Optimally Performing Sensor Substrates through Bio-fouling of Immunoglobulin-Conjugated Gold Nanoparticles

“…Indeed, several factors make Au a desirable material, including easy water dispersal, compatibility with surface functionalization, biological non-reactivity, and ability to be customized (i.e., uniform or different nano-sizes) [23][24][25][26][27]. On the other hand, silicon (Si) or SiO 2 also play an important role in sensing platforms because of its low cost and flexibility for surface modification [28]. Aside from these substrates, platinum (Pt) is also a useful material as biosensor, which is particularly advantageous in animal models due to its biocompatibility and surface stability [29,30].…”

Antimicrobial Potential of Andrographis paniculata Conjugated Gold Nanoparticle

“…Metallic nanoparticles have been used to capture the natural compounds to reveal the antimicrobial activity attributed to the high surface area to the volume ratio of the nanoparticles that allow accommodation of large amount of compounds. Various metallic nanoparticles such as, platinum, silver, and gold were focused recently because of their requisite importance [23,24]. Among the previously mentioned metal nanoparticles, gold nanoparticle (GNP) is more vital because of its history in medicinal application, e.g., treatment of cancer and arthritis with conjugated GNP and also due to their biocompatibility [25][26][27][28][29].…”

SOX-17 Gene Sequence Complementation on Silica-alumina Nanocomposite-modified Dielectrode Surface for Analyzing Gastric Cancer Progression

“…Sensitivity and selectivity are other key factors in the improving biosensor; both are highly correlated with the efficiency in biorecognition through the transducer. Various nanomaterials such as gold, silver, graphene, titanium oxide, silica and alumina were used to improve the bioimmobilization process and the current-flow [16][17][18][19]. Herein, the silica-alumina nanocomposite was utilized to enhance the conductivity in the electrode surface of IDE sensor, and improved the detection of targeted SOX-17 gene sequence.…”