scholarly journals Continuous tuning of the plasmon resonance frequency of porous gold nanoparticles by mixed oxide layers

2020 ◽  
Vol 27 (6) ◽  
pp. 1583-1588
Author(s):  
Laura Juhász ◽  
Bence Parditka ◽  
Péter Petrik ◽  
Csaba Cserháti ◽  
Zoltán Erdélyi
Keyword(s):  
Gold Nanoparticles ◽  
Resonance Frequency ◽  
Mixed Oxide ◽  
High Surface ◽  
Volume Ratio ◽  
Mixture Ratio ◽  
Optical Extinction ◽  
Oxide Layers ◽  
Porous Gold ◽  
Wide Range

Abstract Porous gold nanoparticles (PGNs) are very popular due to their high surface/volume ratio, moreover they have stronger plasmonic properties than their solid counterparts. These properties make the porous gold nanoparticles very useful for lots of applications, for instance chemical sensors, cancer therapy applications. For applications, however, it is indispensable that the resonance frequency (RF) of a plasmonic structure to be tuneable. In this work we show that the RF can be set in a wide range as desired by coating the PGNs by mixed oxide layers. By changing the composition of the coating layer, that is the mixture ratio, the RF can be shifted practically continuously in a wide range determined by the refractive index of the used oxides. As a demonstration, PGNs were coated with mixed alumina-titania oxide layers (5–7 nm) using plasma-enhanced atomic layer deposition method. The oxide layer, beside as a tuning tool, also stabilises the structure of the PGNs when are exposed to elevated temperature. This is shown by the influence of the temperature (from $$350\, ^{\circ }\hbox {C}$$ 350 ∘ C up to $$900\, ^{\circ }\hbox {C}$$ 900 ∘ C ) on the morphology, and as a consequence the optical extinction spectra, of the oxide coated PGNs.

scholarly journals A Review on Biosensors and Recent Development of Nanostructured Materials-Enabled Biosensors

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1109
Author(s):  
Varnakavi. Naresh ◽  
Nohyun Lee
Keyword(s):  
High Surface ◽  
Three Dimensional ◽  
Biological Response ◽  
Volume Ratio ◽  
Recent Decade ◽  
Disease Diagnosis ◽  
Electrical Signal ◽  
Detection Sensitivity ◽  
Wide Range ◽  
Color Tunability

A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.

scholarly journals Graphene-based biosensors

2018 ◽  
Vol 8 (3) ◽  
pp. 20160132 ◽  
Author(s):  
Sabine Szunerits ◽  
Rabah Boukherroub
Keyword(s):  
Biological Samples ◽  
Early Stage ◽  
Point Of Care ◽  
High Surface ◽  
Volume Ratio ◽  
Wide Range ◽  
The Status ◽  
Delays In Diagnosis ◽  
Short Time ◽  
Sensor Interfaces

Reliable data obtained from analysis of DNA, proteins, bacteria and other disease-related molecules or organisms in biological samples have become a fundamental and crucial part of human health diagnostics and therapy. The development of non-invasive tests that are rapid, sensitive, specific and simple would allow patient discomfort to be prevented, delays in diagnosis to be avoided and the status of a disease to be followed up. Bioanalysis is thus a progressive discipline for which the future holds many exciting opportunities. The use of biosensors for the early diagnosis of diseases has become widely accepted as a point-of-care diagnosis with appropriate specificity in a short time. To allow a reliable diagnosis of a disease at an early stage, highly sensitive biosensors are required as the corresponding biomarkers are generally expressed at very low concentrations. In the past 50 years, various biosensors have been researched and developed encompassing a wide range of applications. This contrasts the limited number of commercially available biosensors. When it comes to sensing of biomarkers with the required picomolar (pM) sensitivity for real-time sensing of biological samples, only a handful of sensing systems have been proposed, and these are often rather complex and costly. Lately, graphene-based materials have been considered as superior over other nanomaterials for the development of sensitive biosensors. The advantages of graphene-based sensor interfaces are numerous, including enhanced surface loading of the desired ligand due to the high surface-to-volume ratio, excellent conductivity and a small band gap that is beneficial for sensitive electrical and electrochemical read-outs, as well as tunable optical properties for optical read-outs such as fluorescence and plasmonics. In this paper, we review the advances made in recent years on graphene-based biosensors in the field of medical diagnosis.

scholarly journals Applications of Gold Nanoparticles in Non-Optical Biosensors

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 977 ◽  
Author(s):  
Pengfei Jiang ◽  
Yulin Wang ◽  
Lan Zhao ◽  
Chenyang Ji ◽  
Dongchu Chen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Electrochemical Biosensor ◽  
High Surface ◽  
Volume Ratio ◽  
Optical Biosensors ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Good Biocompatibility

Due to their unique properties, such as good biocompatibility, excellent conductivity, effective catalysis, high density, and high surface-to-volume ratio, gold nanoparticles (AuNPs) are widely used in the field of bioassay. Mainly, AuNPs used in optical biosensors have been described in some reviews. In this review, we highlight recent advances in AuNP-based non-optical bioassays, including piezoelectric biosensor, electrochemical biosensor, and inductively coupled plasma mass spectrometry (ICP-MS) bio-detection. Some representative examples are presented to illustrate the effect of AuNPs in non-optical bioassay and the mechanisms of AuNPs in improving detection performances are described. Finally, the review summarizes the future prospects of AuNPs in non-optical biosensors.

scholarly journals Biosynthesis and characterization of gold nanoparticles using Brazilian red propolis and evaluation of its antimicrobial and anticancer activities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. E. A. Botteon ◽  
L. B. Silva ◽  
G. V. Ccana-Ccapatinta ◽  
T. S. Silva ◽  
S. R. Ambrosio ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Antimicrobial Agents ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
Anticancer Activities

AbstractGold nanoparticles (AuNPs) are highlighted due to their low toxicity, compatibility with the human body, high surface area to volume ratio, and surfaces that can be easily modified with ligands. Biosynthesis of AuNPs using plant extract is considered a simple, low-cost, and eco-friendly approach. Brazilian Red Propolis (BRP), a product of bees, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. Here, we described the biosynthesis of AuNPs using BRP extract (AuNPextract) and its fractions (AuNPhexane, AuNPdichloromethane, AuNPethyl acetate) and evaluated their structural properties and their potential against microorganisms and cancer cells. AuNPs showed a surface plasmon resonance (SPR) band at 535 nm. The sizes and morphologies were influenced by the BRP sample used in the reaction. FTIR and TGA revealed the involvement of bioactive compounds from BRP extract or its fractions in the synthesis and stabilization of AuNPs. AuNPdichloromethane and AuNPhexane exhibited antimicrobial activities against all strains tested, showing their efficacy as antimicrobial agents to treat infectious diseases. AuNPs showed dose-dependent cytotoxic activity both in T24 and PC-3 cells. AuNPdichloromethane and AuNPextract exhibited the highest in vitro cytotoxic effect. Also, the cytotoxicity of biogenic nanoparticles was induced by mechanisms associated with apoptosis. The results highlight a potential low-cost green method using Brazilian red propolis to synthesize AuNPs, which demonstrated significant biological properties.

One-dimensional inorganic semiconductor nanostructures: A new carrier for nanosensors

2010 ◽  
Vol 82 (11) ◽  
pp. 2185-2198 ◽  
Author(s):  
Xiaosheng Fang ◽  
Linfeng Hu ◽  
Changhui Ye ◽  
Lide Zhang
Keyword(s):  
High Performance ◽  
High Surface ◽  
Volume Ratio ◽  
Semiconductor Nanostructures ◽  
One Dimensional ◽  
Semiconductor Nanostructure ◽  
Research Activities ◽  
Wide Range ◽  
Inorganic Semiconductor ◽  
Art Research

One-dimensional (1D) inorganic semiconductor nanostructures have witnessed an explosion of interest over the last decade because of advances in their controlled synthesis and unique property and potential applications. A wide range of gases, chemicals, biomedical nanosensors, and photodetectors have been assembled using 1D inorganic semiconductor nanostructures. The high-performance characteristics of these nanosensors are particularly attributable to the inorganic semiconducting nanostructure high surface-to-volume ratio (SVR) and its rationally designed surface. In this review, we provide a brief summary of the state-of-the-art research activities in the field of 1D inorganic semiconductor nanostructure-based nanosensors. Some perspectives and the outlook for future developments in this area are presented.

scholarly journals Applications of electrospun nanofibers in the biomedical field

SURG Journal ◽  
2012 ◽  
Vol 5 (2) ◽  
pp. 63-73 ◽  
Author(s):  
Nishath Khan
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Ease Of Use ◽  
The Past ◽  
Wide Range ◽  
Novel Method ◽  
Biomedical Field ◽  
Highly Porous

Electrospinning is a technology that has been widely used as a novel method for the generation of nano scale fibres. Electrospun fibres are used in a wide range of applications from electronics to textile. The viability and popularity of this technology can be evidenced by its ease of use and the simplicity of the science behind building the electrospinning machine. The generated fibres have a high surface area- to- volume ratio, the fibrous mats are highly porous and display excellent mechanical properties when compared to other materials of the same scale. In the past decade, this technology has taken off with the use of biocompatible and biodegradable polymers. This review is a summary of the different ways in which electrospinning can be used in the biomedical field. This article analyzes the recent advances of this technology in tissue engineering, drug delivery and in enzyme immobilisation, which once again showcases the versatility of the electrospinning procedure.

scholarly journals Temperature-controlled synthesis of hollow, porous gold nanoparticles with wide range light absorption

2020 ◽  
Vol 55 (12) ◽  
pp. 5257-5267 ◽  
Author(s):  
J. Depciuch ◽  
M. Stec ◽  
A. Maximenko ◽  
J. Baran ◽  
M. Parlinska-Wojtan
Keyword(s):  
Gold Nanoparticles ◽  
Near Field ◽  
Synthesis Method ◽  
Synthesis Temperature ◽  
Porous Gold ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Light Absorbance

AbstractAn easy synthesis method of hollow, porous gold nanoparticles (AuHP NPs) with controlled diameter and pores sizes and with a wide range of light absorbance (continuous between 500 and 900 nm) is presented together with the explanation of the nanoparticle formation mechanism. The NPs were investigated using transmission electron microscopy (TEM) combined with the selected area electron diffraction patterns, X-ray diffraction and ultraviolet–visible spectroscopy. TEM images showed that changing the synthesis temperature allows to obtain AuHP NPs with sizes from 35 ± 4 nm at 60 °C to 76 ± 8 nm at 90 °C. The effects of nanoscale porosity on the far- and near-field optical properties of the nanoparticles, as well as on effective conversion of electromagnetic energy into thermal energy, were applied in simulated photothermal cancer therapy. The latter one was simulated by irradiation of two cancer cell lines SW480 and SW620 with lasers operating at 650 nm and 808 nm wavelengths. The mortality of cells after using the synthesized AuHP NPs as photosensitizers is between 20 and 50% and increases with the decrease in the diameter of the AuHP NPs. All these attractive properties of the AuHP NPs make them find application in many biomedical studies.

Behavioral and Physiological Resistance to Desiccation in Spotted Wing Drosophila (Diptera: Drosophilidae)

2019 ◽  
Vol 48 (4) ◽  
pp. 792-798 ◽  
Author(s):  
Philip D Fanning ◽  
Anne E Johnson ◽  
Benjamin E Luttinen ◽  
Elizabeth M Espeland ◽  
Nolan T Jahn ◽  
...  
Keyword(s):  
Water Loss ◽  
Water Status ◽  
High Surface ◽  
Volume Ratio ◽  
Spotted Wing Drosophila ◽  
Drosophila Suzukii ◽  
Geographical Regions ◽  
Wide Range ◽  
Dry Conditions ◽  
Hot Weather

Abstract With a high surface to volume ratio, small organisms must carefully regulate their internal water status. Spotted-wing drosophila, Drosophila suzukii (Matsumura), is an invasive frugivorous insect distributed across a wide range of geographical regions that can have periods of dry and hot weather, suggesting that this species has strategies to avoid stressful environments and reduce water loss. It also survives winter as an adult fly, indicating that it has adaptations to the low air humidity of this season. To determine the importance of water stress to D. suzukii, we studied their survival in environments of low humidity, which was manipulated using Drierite, and their survival and water loss in response to desiccation. Survival of both sexes was lower in drier conditions, and while female winter morph D. suzukii had higher mortality early on, remaining flies were able to survive longer in the drier conditions than the summer morphs. A bioassay method was adapted from Enjin et al. (2016) using 48-well plates to videotape the location of flies and quantify their behavioral responses to humidity. Male and female D. suzukii avoided dry conditions within the bioassay system, but only when there was at least 25% differential between humidity extremes. This response was observed for both summer and winter morphs of D. suzukii and our results provide guidance for attempts to manipulate crop environments to reduce the economic impact of this pest.

Effects of macroalgal morphology on marine epifaunal diversity

2019 ◽  
Vol 99 (8) ◽  
pp. 1697-1707 ◽  
Author(s):  
Su Xuan Gan ◽  
Ywee Chieh Tay ◽  
Danwei Huang
Keyword(s):  
High Surface ◽  
Algal Species ◽  
High Surface Area ◽  
Three Dimensional ◽  
Volume Ratio ◽  
High Turnover ◽  
Invertebrate Diversity ◽  
Wide Range ◽  
Host Habitat ◽  
Negative Effect

AbstractMacroalgae play important ecological roles, including as hosts for a wide range of epifauna. However, the diversity relationships between macroalgae and epifauna are poorly understood for most tropical host species and algal morphologies. This study aims to characterize and analyse the diversity of invertebrates present amongst macroalgae with three distinct morphologies (three-dimensional, filamentous and foliose) across different tropical intertidal sites in Singapore. Morphological and DNA barcoding tools were employed for epifaunal species identification, and ordination statistics and multiple linear regression were used to test the effects of algal morphology, species and site on community structure and diversity of epiphytic invertebrates. Overall, epifaunal communities were distinct among sites and algal morphologies, and diversity was affected significantly by algal morphology. In particular, filamentous macroalgae hosted the highest abundance of epifauna dominated mainly by amphipods, which were able to take advantage of the high surface area to volume ratio in filamentous algal mats as a consequence of their thinner forms. Foliose species showed a significantly negative effect on invertebrate diversity. Our findings highlight the diverse associations between intertidal macroalgae and invertebrates with high turnover between algal morphology and sites that contribute to the high biodiversity of tropical shores. Future studies should consider the effects of the host habitat, seasonality and more algal species on epifaunal diversity.

Role of Gold Nanoparticles in Drug Delivery and Cancer Therapy

2021 ◽  
pp. 124-140
Author(s):  
Mohammad Nadeem Lone ◽  
Irshad Ahmad Wani ◽  
Gulam Nabi Yatoo ◽  
Zubaid U-Khazir ◽  
Javid Ahmad Banday
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Cancer Therapy ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Drug Carriers ◽  
Photothermal Effect ◽  
Intracellular Release ◽  
High Dispersity

Among various nanoparticles (NPs), gold nanoparticles (GNPs) gained valuable attention in the field of medicine because of some unique properties like small size and high surface area-to-volume ratio, inert nature, stability, high dispersity, non-cytotoxicity, and biocompatibility. These NPs are evolving as promising agents especially in drug carriers, cancer therapy, and constantly being exploring as photothermal agents, contrast agents, and radiosensitisers. Besides, GNPs interact with thiols that provides an effective and selective means of controlled intracellular release. At the present, cancer patients are increasing rapidly at national and international levels. In this chapter, efforts have taken to highlight the importance of GNPs, their critical mediation in drug delivery, as sensors for probing and imaging tumors and anti-angiogenesis. More importantly, this short piece of analysis highlights the photothermal effect of GNPs in therapy and as radiosensitizers. Finally, the current challenges and future perspectives of GNP's in cancer management are also discussed.

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