Nanomaterials for targeted detection and photothermal killing of bacteria

Abstract

Despite the modern treatment processes, contamination of food, water and medical equipment by pathogenic bacteria is very common in this world. Since the last two decades, one of the most important and complex problems our society has been facing is that several human pathogens became resistant to most of the clinically approved antibiotics. Recent advancement in nanoscience and nanotechnology has expanded our ability to design and construct nanomaterials with targeting, therapeutic, and diagnostic functions. These multifunctional materials have attracted our attention to be used as the promising tool for selective bacteria sensing and therapy without the current drugs. This tutorial review provides the basic concepts and critical properties of the different nanostructures that are useful for the pathogen detection and photothermal applications. In addition, bio-conjugated nanomaterial based strategies have been discussed with the aim to provide readers an overview of exciting opportunities and challenges in this field.

Reduced graphene oxide–titania based platform for label-free biosensor

“…The linear t of the RGO-ant-TiO 2 /ITO electrode exhibits a nearly straight line, as a result of increased diffusion compared to that of the bare ITO (curve a). This may be due to the presence of an increased concentration of defects in the RGO-ant-TiO 2 nanohybrid that perhaps inhibits the direct electron ow from the redox probe [Fe(CN) 6 ] 3À/4À to the electrode surface. However, aer the immobilization of Ab-Vc and BSA on the RGO-ant-TiO 2 /ITO surface, the diffusion of electrons between the electrode and the redox ions decreases, resulting in an increase in the R p value (2.28 kU, 2.89 kU; curve c & d).…”

“…This may due to antigen-antibody interactions on the transducer surface, which block the charge transfer from the electrolyte to the electrode. The transfer of electrons from the [Fe(CN) 6 ] 3À/4À redox reaction may be blocked due to the formation of highly organized layers on the electrode surface, because these redox species do not penetrate the layer and reach the conductive electrode surface. With the addition of the Vc moieties to the BSA/Ab-Vc/RGO-ant-TiO 2 /ITO immunoelectrode, these Vc protein molecules form an insulating layer on the electrode, resulting in the increased diameter of the semicircle, implying higher charge transfer resistance.…”

“…Transmission electron microscopy (TEM, Tecnai-G2F30STWINT), scanning electron microscopy (SEM LEO 440) and atomic force microscopy (AFM, Park Systems XE70) were used to investigate the structural and morphological properties of RGO-ant-TiO 2 and BSA/Ab-Vc/RGO-ant-TiO 2 . The electrochemical analysis was conducted using an Autolab Potentiostat/ Galvanostat with a three-electrode system consisting of a working electrode, platinum wire as the auxiliary electrode, and Ag/AgCl acting as the reference electrode in phosphate buffer saline (PBS, pH 7.0, 0.9% NaCl) containing 5 mM [Fe(CN) 6 ] 3À/4À as the redox probe.…”

“…[1][2][3][4] Multifunctional nanomaterials have been found to be promising candidates for the sensitive and selective detection of pathogens, smRNA, PNA, aptamers, etc. 5,6 Carbon allotropes, like graphene oxide (GO), fullerenes, carbon nanotubes, etc., have been explored for cellular imaging, tissue engineering, intercalation materials, drug delivery biomaterials and biosensors. [7][8][9][10][11] For biosensor fabrication, the presence of available functional groups (e.g.…”

Ultrasmall Conjugated Polymer Nanoparticles with High Specificity for Targeted Cancer Cell Imaging

“…With the rapid advances of nanotechnology, versatile NP systems including semiconducting quantum dots (QDs), gold NPs, and dye encapsulated NPs, etc., have been developed 12, 13, 14, 15, 16. Despite the fact that NPs with varied sizes have been designed for different biomedical applications,17, 18, 19 there has been limited success in highly selective cancer targeting, and only a few examples for inorganic gold NPs were reported 16, 20. This is attributed to the precise size control of inorganic NPs to be smaller than 10 nm, as NPs with sizes ranging from 20 to 200 nm are able to be nonspecific internalized into cells which significantly compromises the detection selectivity 21, 22, 23, 24, 25.…”