Advanced Materials Letters

Gold nanoparticles (GNPs) are of unique and interesting materials being firstly reported 100 years ago. They are one of the most widely studied nanomaterials potential for disease cure. To improve the colloidal stability, biocompatibility, and hemocompatibility of GNPs, chitosan (CS), a naturally produced polysaccharide with excellent biocompatibility and biodegradation, has been modified to generate water-soluble derivatives and used as the stabilizing agent of GNPs. In the presence of these derivatives, GNPs are stabilized, functionalized, and assembled via electronic static and covalent bond interactions. Based on these works, GNPs with different dimensional, morphology, and crystal lattice are obtained, which can be further apply to a variety of applications in sensing, imaging, therapy, and catalysis. 

Monitoring systems that are capable to record neuronal activity in in-vitro cell cultures are prerequisite to the comprehensive investigation of neuronal processes. Low temperature cofired ceramics are a suitable platform for rapid prototyping of biological reactors, entailing a wide assortment of integration-capable sensors. Neuronal spikes capture is fundamental for understanding of the signal propagation within the neuronal network. It requires reliable electrodes, which can be arranged 3-dimensionally in an in vitro cell culture. Thick film gold electrodes have been proven for such applications, however their characteristics especially at small dimensions stray strongly. This work investigates thin films separating small thick film gold electrodes and an electrolyte solution with regard to their influence on the charge transport processes in such systems. PEDOT:PSS layer and TiOxNy deposited on LTCC gold electrodes, including their impedance characteristics are discussed and compared. TiOxNy layers with serial resistance Rs of 32 kΩ and serial capacitance Cs of 4.1 pF measured at 1 kHz are proposed to be the used as sensing elements in 3-dimensional in vitro cell cultures.                                                                       

International Association of Advanced Materials is pleased to announce Sensors & Actuators Conference Series in Asia, Europe and America with collaboration of VBRI Press AB, Sweden. The conference series are dedicated on the technology and systems in the field of sensors, actuators, microsystems and their developments, and major challenges in research & developments and markets.

In this work we have successfully prepared spherical and chain type silver nanoparticles of excellent size’s homogeneity, reproducibility and stability using tannic acid. The synthesized nanometallic structures were characterized for their shape, size, thermal stability and crystalline nature. The mechanism for the formation of Ag NPs and shape evolution of the chain structure has been vividly explained. Further, these NPs were found to exhibit significant antibacterial activity against gram negative Escherichia coli bacteria but to different extend indicating the influence of particles morphology on their antibacterial behaviours.

Nanoparticles (NPs) having well-defined shape, size and clean surface serve as ideal model system to investigate surface/interfacial reactions. Ag and Al NPs are receiving great interest due to their wide applications in bio-medical field, aerospace and space technology as combustible additives in propellants and hydrogen generation. Hence, in this study, we have synthesized Ag and Al NPs using an innovative approach of ultra-sonic dissociation of thin films. Phase and particle size distributions of the Ag and Al NPs have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thin film dissociation/dissolution mechanism, hence conversion into NPs has been characterized by SEM- scanning electron microscope. EDXA & ICPMS have been performed for chemical analysis of NPs. Optical properties have been characterized by UV-Vis and PL spectroscopy. These NPs have also been investigated for their anti-bacterial activity against Escherichia coli bacteria. To the best of our knowledge, this is the first time when NPs has been synthesized by ultra-sonic dissociation of thin films. As an application, these NPs were used further for synthesis of nanocomposite polymer membranes, which show excellent activity against bio film formation.  

Novel spin-labeled magnetic nanoparticles (MNPs) were prepared through the reaction between carboxylic acids modified Fe3O4 particles and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO). And X-ray diffractometer (XRD), FT-IR spectra, thermogravimetric analysis (TGA), transmission electronic microscopy (TEM) and room temperature electron paramagnetic resonance (EPR) were employed to characterize the prepared materials. The results of EPR measurements indicated that the spin-labeled MNPs exhibited both the paramagnetism of nitroxide free radicals and superparamagnetism of ferrimagnetic nanoparticles could act as a bio-probe or potential drug delivery vehicles tracking by EPR technique.

Over the past few years, bionanomaterial research has emerged as a new exciting field and the importance of DNA, RNA and peptides in designing bionanomaterials for the fundamental development in biotechnology and nanomaterials has begun to be recognized as a new interdisciplinary frontier in field of life science and material science. Great advances in nanobiochip materials, nanoscale biomimetic materials, nanomotors, nanocomposite materials, interface biomaterials, and nanobiosensor and nano drug delivery systems have enormous prospect in industrial, defense, and clinical medicine applications. Bio-molecules are very important elements in nanoscience and nanotechnology. Peptide nucleic acids (PNAs) replace DNA as a probe for biomolecular tool in the molecular genetics diagnostics, cytogenetic, and various pharmaceutical potentials as well as for the development of sensors/arrays/chips and many more purposes.