Surface

Wu, L., Y. Xiang and Y. Qin - CH(3)NH(3)PbBr(3) Thin Film Served as Guided-Wave Layer for Enhancing the Angular Sensitivity of Plasmon Biosensor. Biosensors 11: 415; (2021). Goto reference

CH(3)NH(3)PbBr(3) perovskite thin film is used as a guided-wave layer and coated on the surface of an Au film to form the Au-perovskite hybrid structure. Using the hybrid structure, a perovskite-based guided-wave surface plasmon resonance (GWSPR) biosensor is proposed with high angular sensitivity. First, it is found that the electric field at the sensing interface is improved by the CH(3)NH(3)PbBr(3) perovskite thin film, thereby enhancing the sensitivity. The result demonstrates that the angular sensitivity of the Au-perovskite-based GWSPR biosensor is as high as 278.5°/RIU, which is 110.2% higher than that of a conventional Au-based surface plasmon resonance (SPR) biosensor. Second, the selection of the coupling prism in the configuration of the GWSPR biosensor is also analyzed, and it indicates that a low refractive index (RI) prism can generate greater sensitivity. Therefore, the low-RI BK7 prism is served as the coupling prism for the proposed GWSPR biosensor. Finally, the proposed GWSPR sensing structure can not only be used for liquid sensing, but also for gas sensing, and it has also been demonstrated that the GWSPR gas sensor is 2.8 times more sensitive than the Au-based SPR gas sensor.

Papalia, Giuseppe and Myszka, David - Exploring minimal biotinylation conditions for biosensor analysis using capture chips. Analytical Biochemistry 403: 30-35; (2010). Goto reference

Using Biacore's new regenereteable streptavidin capture (CAP) sensor chips, a number of biotinylation conditions for target ligands were investigated. For instance the use of the standard amine as well as the less commonly used carboxyl biotinylation methods, the time scales required for efficient biotinylation as well as the hazards of overbiotinylation. In Addition a range of desalting methods, including spin columns, dialysis membranes, and filters is tested to remove excess biotin. Finally, the effects of common buffer components, such as Tris and glycerol, on the biotinylation process are tested. Together, this publication can serve as a general guide of the steps to consider when minimally biotinylating a target ligand.

Hahn, C. D. et al - Self-assembled monolayers with latent aldehydes for protein immobilization. Bioconjugate Chemistry 18: 247-253; (2007).

Aldehyde functions are widely used for immobilization of biomolecules on glass surfaces but have found little attention for biofunctionalization of self-assembled monolayers (SAMs) on gold, due to interference between thiol and aldehyde functions. This problem was recently solved by synthesis of an alkanethiol that carried a vicinal diol group [Jang et al. (2003) Nano Lett. 3, 691-694]. In this article, a general modular strategy was introduced by which SAM components with vicinal diol functions were rapidly synthesized with high yield.

Kyprianou, Dimitris et al - New reactive polymer for protein immobilisation on sensor surfaces. Biosensors and Bioelectronics 24: 1365-1371; (2009). Goto reference

A novel protocol for the covalent immobilisation of biomolecules containing primary amines using an inexpensive and simple polymer is presented. The reactivity of the polymer is based on the reaction between primary amines and thioacetal groups included in the polymer network. These functional groups (thioacetal) do not need any further activation in order to react with proteins, making it attractive for sensor fabrication. The novel polymer also contains thiol derivative groups (disulphide groups or thioethers) that promote self-assembling on a metal transducer surface.