Photoluminescent gold nanodots (Au NDs) are prepared via etching and codeposition of hybridized ligands, an antimicrobial peptide (surfactin; SFT), and 1-dodecanethiol (DT), on gold nanoparticles (≈3.2 nm). As-prepared ultrasmall SFT/DT–Au NDs (size ≈2.5 nm) are a highly efficient antimicrobial agent. The photoluminescence properties and stability as well as the antimicrobial activity of SFT/DT–Au NDs are highly dependent on the density of SFT on Au NDs. Relative to SFT, SFT/DT–Au NDs exhibit greater antimicrobial activity, not only to nonmultidrug-resistant bacteria but also to the multidrug-resistant bacteria. The minimal inhibitory concentration values of SFT/DT–Au NDs are much lower (>80-fold) than that of SFT. The antimicrobial activity of SFT/DT–Au NDs is mainly due to the synergistic effect of SFT and DT–Au NDs on the disruption of the bacterial membrane. In vitro cytotoxicity and hemolysis analyses have revealed superior biocompatibility of SFT/DT–Au NDs than that of SFT. Moreover, in vivo methicillin-resistant S. aureus–infected wound healing studies in rats show faster healing, better epithelialization, and are more efficient in the production of collagen fibers when SFT/DT–Au NDs are used as a dressing material. This study suggests that the SFT/DT–Au NDs are a promising antimicrobial candidate for preclinical applications in treating wounds and skin infections.

Self-Assembly of Antimicrobial Peptides on Gold Nanodots: Against Multidrug-Resistant Bacteria and Wound-Healing Application

Biosensors for breast cancer diagnosis: A review of bioreceptors, biotransducers and signal amplification strategies

Recently, graphene has been extensively researched in fundamental science and engineering fields and has been developed for various electronic applications in emerging technologies owing to its outstanding material properties, including superior electronic, thermal, optical and mechanical properties. Thus, graphene has enabled substantial progress in the development of the current electronic systems. Here, we introduce the most important electronic and thermal properties of graphene, including its high conductivity, quantum Hall effect, Dirac fermions, high Seebeck coefficient and thermoelectric effects. We also present up-to-date graphene-based applications: optical devices, electronic and thermal sensors, and energy management systems. These applications pave the way for advanced biomedical engineering, reliable human therapy, and environmental protection. In this review, we show that the development of graphene suggests substantial improvements in current electronic technologies and applications in healthcare systems.

Electronic and Thermal Properties of Graphene and Recent Advances in Graphene Based Electronics Applications

Green synthesis of gold nanoparticles using brown algae Cystoseira baccata: Its activity in colon cancer cells

In recent years, nanoplasmonic sensors have become widely used for the label-free detection of biomolecules across medical, biotechnology, and environmental science applications. To date, many nanoplasmonic sensing strategies have been developed with outstanding measurement capabilities, enabling detection down to the single-molecule level. One of the most promising directions has been surface-based nanoplasmonic sensors, and the potential of such technologies is still emerging. Going beyond detection, surface-based nanoplasmonic sensors open the door to enhanced, quantitative measurement capabilities across the biointerfacial sciences by taking advantage of high surface sensitivity that pairs well with the size of medically important biomacromolecules and biological particulates such as viruses and exosomes. The goal of this review is to introduce the latest advances in nanoplasmonic sensors for the biointerfacial sciences, including ongoing development of nanoparticle and nanohole arrays for exploring different classes of biomacromolecules interacting at solid–liquid interfaces. The measurement principles for nanoplasmonic sensors based on utilizing the localized surface plasmon resonance (LSPR) and extraordinary optical transmission (EOT) phenomena are first introduced. The following sections are then categorized around different themes within the biointerfacial sciences, specifically protein binding and conformational changes, lipid membrane fabrication, membrane–protein interactions, exosome and virus detection and analysis, and probing nucleic acid conformations and binding interactions. Across these themes, we discuss the growing trend to utilize nanoplasmonic sensors for advanced measurement capabilities, including positional sensing, biomacromolecular conformation analysis, and real-time kinetic monitoring of complex biological interactions. Altogether, these advances highlight the rich potential of nanoplasmonic sensors and the future growth prospects of the community as a whole. With ongoing development of commercial nanoplasmonic sensors and analytical models to interpret corresponding measurement data in the context of biologically relevant interactions, there is significant opportunity to utilize nanoplasmonic sensing strategies for not only fundamental biointerfacial science, but also translational science applications related to clinical medicine and pharmaceutical drug development among countless possibilities.

R. Viswambari Devi

Papers

Nanomaterials for early detection of cancer biomarker with special emphasis on gold nanoparticles in immunoassays/sensors.

Lockdown of mitochondrial Ca2+ extrusion and subsequent resveratrol treatment kill HeLa cells by Ca2+ overload.