scholarly journals Enzyme Immobilization on Gold Nanoparticles for Electrochemical Glucose Biosensors

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1156
Author(s):  
Wiktoria Lipińska ◽  
Katarzyna Grochowska ◽  
Katarzyna Siuzdak
Keyword(s):  
Gold Nanoparticles ◽  
Enzyme Immobilization ◽  
Experimental Approach ◽  
Limit Of Detection ◽  
Glucose Sensing ◽  
Self Assembled Monolayer ◽  
Glucose Biosensors ◽  
The Past ◽  
Exponential Trend ◽  
Immobilization Techniques

More than 50 years have passed since Clark and Lyon developed the concept of glucose biosensors. Extensive research about biosensors has been carried out up to this day, and an exponential trend in this topic can be observed. The scope of this review is to present various enzyme immobilization methods on gold nanoparticles used for glucose sensing over the past five years. This work covers covalent bonding, adsorption, cross-linking, entrapment, and self-assembled monolayer methods. The experimental approach of each modification as well as further results are described. Designated values of sensitivity, the limit of detection, and linear range are used for the comparison of immobilization techniques.

Indirect Determination of Amikacin by Gold Nanoparticles as Redox Probe

2020 ◽  
Vol 17 ◽  
Author(s):  
Mansureh Alizadeh ◽  
Mandana Amiri ◽  
Abolfazl Bezaatpour
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Cathodic Peak ◽  
Easy Method ◽  
Peak Current ◽  
Indirect Determination ◽  
Tract Infections

: Amikacin is an aminoglycoside antibiotic used for many gram-negative bacterial infections like infections in the urinary tract, infections in brain, lungs and abdomen. Electrochemical determination of amikacin is a challenge in electroanalysis because it shows no voltammetric peak at the surface of bare electrodes. In this approach, a very simple and easy method for indirect voltammetric determination of amikacin presented in real samples. Gold nanoparticles were electrodeposited at the surface of glassy carbon electrode in constant potential. The effect of several parameters such as time and potential of deposition, pH and scan rates on signal were studied. The cathodic peak current of Au3+ decreased with increasing amikacin concentration. Quantitative analysis of amikacin was performed using differential pulse voltammetry by following cathodic peak current of gold ions. Two dynamic linear ranges of 1.0 × 10−8–1.0 × 10-7 M and 5.0 × 10−7–1.0 × 10-3 M were obtained and limit of detection was estimated 3.0× 10−9 M. The method was successfully determined amikacin in pharmaceutical preparation and human serum. The effect of several interference in determination of amikacin was also studied.

scholarly journals Potential application of gold nanoparticles in food packaging: a mini review

Gold Bulletin ◽  
2021 ◽  
Author(s):  
Saeed Paidari ◽  
Salam Adnan Ibrahim
Keyword(s):  
Gold Nanoparticles ◽  
Potential Application ◽  
Food Industry ◽  
Food Packaging ◽  
Industrial Applications ◽  
Mechanisms Of Action ◽  
Microbial Load ◽  
Food Sector ◽  
The Past ◽  
Industry Applications

AbstractIn the past few decades, there have been remarkable advances in our knowledge of gold nanoparticles (AuNPs) and synthesizing methods. AuNPs have become increasingly important in biomedical and industrial applications. As a newly implemented method, AuNPs are being used in nanopackaging industries for their therapeutic and antibacterial characteristics as well as their inert and nontoxic nature. As with other NPs, AuNPs have privileges and disadvantages when utilized in the food sector, yet a significant body of research has shown that, due to the specific nontoxic characteristics, AuNPs could be used to address other NP flaws. In this mini review, we present synthesizing methods, food industry applications, and mechanisms of action of gold nanoparticles. Regarding the investigations, gold nanoparticles can play a major role to reduce microbial load in foodstuff and therefore can be implemented in food packaging as an effective approach.

scholarly journals Ratiometric Fluorescent Biosensors for Glucose and Lactate Using an Oxygen-Sensing Membrane

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 208
Author(s):  
Hong Dinh Duong ◽  
Jong Il Rhee
Keyword(s):  
Limit Of Detection ◽  
Oxygen Sensing ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Oxidation Reactions ◽  
Lactate Oxidase ◽  
Lactate Oxidation ◽  
Detection Range ◽  
Quenching Effect ◽  
Sensing Membrane

In this study, ratiometric fluorescent glucose and lactate biosensors were developed using a ratiometric fluorescent oxygen-sensing membrane immobilized with glucose oxidase (GOD) or lactate oxidase (LOX). Herein, the ratiometric fluorescent oxygen-sensing membrane was fabricated with the ratio of two emission wavelengths of platinum meso-tetra (pentafluorophenyl) porphyrin (PtP) doped in polystyrene particles and coumarin 6 (C6) captured into silica particles. The operation mechanism of the sensing membranes was based on (i) the fluorescence quenching effect of the PtP dye by oxygen molecules, and (ii) the consumption of oxygen levels in the glucose or lactate oxidation reactions under the catalysis of GOD or LOX. The ratiometric fluorescent glucose-sensing membrane showed high sensitivity to glucose in the range of 0.1–2 mM, with a limit of detection (LOD) of 0.031 mM, whereas the ratiometric fluorescent lactate-sensing membrane showed the linear detection range of 0.1–0.8 mM, with an LOD of 0.06 mM. These sensing membranes also showed good selectivity, fast reversibility, and stability over long-term use. They were applied to detect glucose and lactate in artificial human serum, and they provided reliable measurement results.

scholarly journals Surface Plasmon Resonance Assay for Label-Free and Selective Detection of HIV-1 p24 Protein

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 180
Author(s):  
Lucia Sarcina ◽  
Giuseppe Felice Mangiatordi ◽  
Fabrizio Torricelli ◽  
Paolo Bollella ◽  
Zahra Gounani ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Covalent Binding ◽  
Hiv Infections ◽  
Selectivity Ratio ◽  
Selective Detection ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Label Free Detection ◽  
P24 Protein ◽  
Hiv 1

The early detection of the human immunodeficiency virus (HIV) is of paramount importance to achieve efficient therapeutic treatment and limit the disease spreading. In this perspective, the assessment of biosensing assay for the HIV-1 p24 capsid protein plays a pivotal role in the timely and selective detection of HIV infections. In this study, multi-parameter-SPR has been used to develop a reliable and label-free detection method for HIV-1 p24 protein. Remarkably, both physical and chemical immobilization of mouse monoclonal antibodies against HIV-1 p24 on the SPR gold detecting surface have been characterized for the first time. The two immobilization techniques returned a capturing antibody surface coverage as high as (7.5 ± 0.3) × 1011 molecule/cm2 and (2.4 ± 0.6) × 1011 molecule/cm2, respectively. However, the covalent binding of the capturing antibodies through a mixed self-assembled monolayer (SAM) of alkanethiols led to a doubling of the p24 binding signal. Moreover, from the modeling of the dose-response curve, an equilibrium dissociation constant KD of 5.30 × 10−9 M was computed for the assay performed on the SAM modified surface compared to a much larger KD of 7.46 × 10−5 M extracted for the physisorbed antibodies. The chemically modified system was also characterized in terms of sensitivity and selectivity, reaching a limit of detection of (4.1 ± 0.5) nM and an unprecedented selectivity ratio of 0.02.

scholarly journals Label-Free Electrochemical Biosensor Based on Au@MoS₂–PANI for Escherichia coli Detection

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 49
Author(s):  
Pushap Raj ◽  
Man Hwan Oh ◽  
Kyudong Han ◽  
Tae Yoon Lee
Keyword(s):  
Escherichia Coli ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Bacterial Pathogens ◽  
Cost Effective ◽  
Covalent Immobilization ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Detection Range ◽  
Linear Detection

Bacterial infections have become a significant challenge in terms of public health, the food industry, and the environment. Therefore, it is necessary to address these challenges by developing a rapid, cost-effective, and easy-to-use biosensor for early diagnosis of bacterial pathogens. Herein, we developed a simple, label-free, and highly sensitive immunosensor based on electrochemical detection using the Au@MoS₂–PANI nanocomposite. The conductivity of the glassy carbon electrode is greatly enhanced using the Au@MoS₂–PANI nanocomposite and a self-assembled monolayer of mercaptopropionic acid on the gold nanoparticle surface was employed for the covalent immobilization of antibodies to minimize the nonspecific adsorption of bacterial pathogens on the electrode surface. The biosensor established a high selectivity and sensitivity with a low limit of detection of 10 CFU/mL, and detected Escherichia coli within 30 min. Moreover, the developed biosensor demonstrated a good linear detection range, practical utility in urine samples, and electrode regenerative studies.

Acetylcholinesterase Biosensor Based on Gold Nanoparticles and Cysteamine Self Assembled Monolayer for Determination of Monocrotophos

2009 ◽  
Vol 9 (4) ◽  
pp. 2368-2373 ◽  
Author(s):  
Dan Du ◽  
Wenjuan Chen ◽  
Jie Cai ◽  
Jianming Zhang ◽  
Haiyang Tu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Self Assembled Monolayer ◽  
Self Assembled

scholarly journals Quantification of DNA by a Thermal-Durable Biosensor Modified with Conductive Poly(3,4-ethylenedioxythiophene)

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3684 ◽  
Author(s):  
Yesong Gu ◽  
Po-Yuan Tseng ◽  
Xiang Bi ◽  
Jason Yang
Keyword(s):  
Gold Nanoparticles ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
Complementary Sequence ◽  
Signal Decay ◽  
Target Dna ◽  
Hybridization Efficiency ◽  
Sh Group ◽  
Polymerase Chain ◽  
Or Gene

The general clinical procedure for viral DNA detection or gene mutation diagnosis following polymerase chain reaction (PCR) often involves gel electrophoresis and DNA sequencing, which is usually time-consuming. In this study, we have proposed a facile strategy to construct a DNA biosensor, in which the platinum electrode was modified with a dual-film of electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) resulting in immobilized gold nanoparticles, with the gold nanoparticles easily immobilized in a uniform distribution. The DNA probe labeled with a SH group was then assembled to the fabricated electrode and employed to capture the target DNA based on the complementary sequence. The hybridization efficiency was evaluated with differential pulse voltammetry (DPV) in the presence of daunorubicin hydrochloride. Our results demonstrated that the peak current in DPV exhibited a linear correlation the concentration of target DNA that was complementary to the probe DNA. Moreover, the electrode could be reused by heating denaturation and re-hybridization, which only brought slight signal decay. In addition, the addition of the oxidized form of nicotinamide adenine dinucleotide (NAD+) could dramatically enhance the sensitivity by more than 5.45-fold, and the limit-of-detection reached about 100 pM.

scholarly journals Feeding Experiments on Vittina Turrita (Mollusca, Gastropoda, Neritidae) Reveal Tooth Contact Areas and Bent Radular Shape During Foraging

2021 ◽  
Author(s):  
WENCKE KRINGS ◽  
CHRISTINE HEMPEL ◽  
LISA SIEMERS ◽  
MARCO NEIBER ◽  
STANISLAV GORB
Keyword(s):  
Experimental Approach ◽  
Tooth Wear ◽  
Ecological Niches ◽  
Control Group ◽  
Contact Areas ◽  
The Past ◽  
Feeding Experiments ◽  
Feeding Structure ◽  
3D Architecture ◽  
Area And Volume

Abstract The radula is the food gathering and processing structure and one important autapomorphy of the Mollusca. It is composed of a chitinous membrane with small, embedded teeth representing the interface between the organism and its ingesta. In the past, various approaches aimed at connecting the tooth shapes, which are highly distinct within single radulae due to their different functions. However, conclusions from the literature have been mainly drawn from microscopical analyses of mounted radulae, but the real interacting radular parts – even though the precise contact areas are essential for determining a tools functionality – and the 3D architecture of this complex feeding structure have not been previously determined. In the experimental approach presented here individuals of Vittina turrita (Neritidae, Gastropoda) were fed with algae paste attached to different sandpaper types. By comparison with radulae from a control group, sandpaper-induced tooth wear patterns were identified and both the area and volume loss were quantified. In addition to the exact contact area of each tooth, conclusions about the 3D position of teeth and the radular bending during feeding motion could be drawn. Furthermore, hypotheses about the specific functions of individual tooth types could be put forward. This kind of feeding experiments under controlled conditions is new for Mollusca and may provide a good basis for future studies on the radula functional morphology. It can be potentially applied to species with distinct tooth morphologies and ecological niches.

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