Fundamentals and application of ordered molecular assemblies to affinity biosensing

Abstract

Organization of biomolecules in two/three dimensional assemblies has recently aroused much interest in nanobiotechnology. In this context, the development of techniques for controlling spatial arrangement and orientation of the desired molecules to generate highly-ordered nanostructures in the form of a mono/multi layer is considered highly significant. The studies of monolayer films to date have focused on three distinct methods of preparation: (i) the Langmuir-Blodgett (LB) technique, involving the transfer of a monolayer assembled at the gas-liquid interface; (ii) self-assembly at the liquid-solid interface, based on spontaneous adsorption of desired molecules from a solution directly onto a solid surface; and (iii) Layer-by-layer (LBL) self-assembly at a liquid-solid interface, based on inter-layer electrostatic attractions for fabrication of multilayers. A variety of monolayers have been utilized to fabricate biomolecular electronic devices including biosensors. The composition of a monolayer based matrix has been found to influence the activity(ies) of biomolecule(s). We present comprehensive and critical analysis of ordered molecular assemblies formed by LB and self-assembly with potential applications to affinity biosensing. This critical review on fundamentals and application of ordered molecular assemblies to affinity biosensing is likely to benefit researchers working in this as well as related fields of research (401 references).

Ascorbic acid-triggered electrochemical–chemical–chemical redox cycling for design of enzyme-amplified electrochemical biosensors on self-assembled monolayer-covered gold electrodes

“…Among the commonly used ALP substrate/product couples, including 4-aminophenyl phosphate (p-APP)/4-aminophenol (p-AP), hydroquinone diphosphate (HQDP)/hydroquinone (HQ), L-ascorbic acid 2-phosphate (AAP)/L-ascorbic acid (AA), 4-amino-1-naphthyl phosphate (ANP)/4-amino-1-naphthol (AN) and 1-naphthyl phosphate (NPP)/1-naphthol (NP), AAP is better because of its low cost, the easy dissolution of AAP and AA in aqueous solutions, the high formal potential of AAP and low formal potential of AA and the high signal-to-background ratio [20]. Self-assembled monolayer (SAM) on gold has been used frequently for controlling the adsorption of biomolecules and developing electrochemical biosensors [1,[25][26][27]. SAM is a more convenient (and more effective) choice for modifying electrodes in electrochemistry than Langmuir-Blodgett films or nonspecific physisorbed films because it forms spontaneously, is easy to handle mechanically, and does not desorb readily [28].…”

Antibody Oriented Immobilization on Gold using the Reaction between Carbon Disulfide and Amine Groups and Its Application in Immunosensing

“…9,10 For immunosensors prepared on gold, alkanethiol-based self-assembled monolayers (SAMs) 11−17 are among the most popular surface modification strategies, because they can be easily prepared to form a highly organized and ultrastable organic thin film in nanometer scale with good reproducibility. 15,18 If carboxylic functions are the terminal groups of SAMs, they can be used to covalently immobilize compounds with amine groups after an activation process, such as with N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC).…”

Nanostructured platform for the detection of Neisseria gonorrhoeae using electrochemical impedance spectroscopy and differential pulse voltammetry

“…Besides this, it should be interesting to fabricate ordered molecular assemblies [47] based on PANIFe 3 O 4 nanocomposite for application to nucleic acid sensor.…”