Metal–organic frameworks (MOFs) are porous coordination polymers (CP) produced by metal-based nodes and multitopic organic ligands. Based on their porous and microcrystalline powder structures, they ...have initially been used for storage, catalysis and separation. Then, because of their advantageous properties like ease of the tailoring, they also have been applied in areas like chemical sensing, biological applications, etc. The CPs were combined with molecules such as organic dyes, small biomolecules, nanomaterials like nanoparticles, nanowires, nanofibers and polymers and as a result, composite MOFs have been produced. By this way, better mechanical stability, conductivity, and catalytic performance were obtained. This review (with 135 refs.) summarizes the progress made in the past years in the field of electrochemical and optical sensing based on the use of MOFs. Following an introduction into the field, large sections cover MOF based sensors exploiting (a) carbon nanomaterials (with subsections on carbon nanotubes, graphene and its derivatives), (b) metal/metal oxide MOFs; including gold, silver, copper and/or copper oxide nanoparticle and other metal/MOF composites. Enzyme mimicking MOFs are discussed next. In this context, after the brief information about focused MOFs, the nanomaterial/MOF composites were discussed and related examples were presented.
Graphical abstract
MOF structures in Sensing Systems.
Display omitted
The illustration of the influenza virüs A path in the host cells.
•Information about the structure, species and pandemics of influenza A virus has been presented.•The invasion of host ...cells by this virus is explained.•Conventional detection methods have been discussed.•Existing electrochemical influenza A virus biosensors have been critically evaluated.•The prospects of electrochemical influenza A virus biosensors have been critically evaluated.
Influenza virus A still causes serious pandemics every year which result in high mortality. Though there are promising developments involving newly emerged diagnostic tests for the detection of this virus, the “perfect” test has not been developed yet. In this review, we focus on the electrochemical biosensors for influenza virus A detection. Firstly, brief information about structure, species and pandemics of influenza virus A has been presented. After elucidating the invasion of host cells with this virus, conventional detection methods have been discussed. Then, definition of electrochemical biosensors was made and the existing electrochemical influenza virus A biosensors have been critically evaluated. Lastly, the prospects of electrochemical influenza virus A biosensor in POC technology have been discussed.
A composite electrode was prepared by modifying glassy carbon microparticles with gold nanoparticles (Au-nps) and xanthine oxidase enzyme (XOD) for xanthine (X) and hypoxanthine (Hx) detection. After ...the optimization of the system for X, the biosensor was characterized for X and Hx. A linearity was obtained in the concentration range between 5.00
×
10
−7 and 1.00
×
10
−5
M for X with equation of
y
=
0.24
x
+
0.712 and 5.00
×
10
−6 to 1.50
×
10
−4
M for Hx, with equation of
y
=
0.014
x
+
0.575, respectively. Obtained results were compared to X and/or Hx biosensors including/not including Au-np in the structure. The developed system was also applied for detection of Hx in canned tuna fish sample and very promising results were obtained.
Neuroaminidase (NA) enzyme is a kind of glycoprotein that is found on the influenza A virus. During infection, NA is important for the release of influenza virions from the host cell surface together ...with viral aggregates. It may also be involved in targeting the virus to respiratory epithelial cells. In this study, a model electrochemical influenza A viral biosensor in which receptor-binding properties have been based on NA was developed for the first time. The biosensor’s working principle is based on monitoring the interactions between fetuin A and NA enzyme. The assay was monitored step by step by using electrochemical impedance spectroscopy.
An effective electrochemical influenza A biosensor based on a graphene-gold (Au) hybrid nanocomposite modified Au-screen printed electrode has been developed. The working principle of the developed ...biosensor relies on the measurement of neuraminidase (N) activity. After the optimization of experimental parameters like the effect of bovine serum albumin addition and immobilization times of fetuin A and PNA lectin, the analytical characteristics of the influenza A biosensor were investigated. As a result, a linear range between 10
U mL
and 10
U mL
was found with a relative standard deviation value of 3.23% (for 10
U mL
of N, n:3) and a limit of detection value of 10
U mL
N. The developed biosensor was applied for real influenza virus A (H9N2) detection and very successful results were obtained.
Glassy carbon paste electrode (GCPE) was modified with graphene platinum hybrid nanoparticle (Gr–Pt hybrid NP) and used as a transducer for label and indicator free electrochemical genosensor. 22 mer ...oligonucleotides representing Escherichia coli bacteria were used as a model case. As far as it is known, this study is the first study where Gr–Pt hybrid NP was incorporated into GCPE and used for genosensor transducer. The extent of hybridization was determined by using differential pulse voltammetric signals of guanin oxidation. After the optimization of experimental parameters, analytical characteristics were investigated. The linear range was found between 1.5×10−7 and 2.25×10−6M with the equation of y=1.6566x−2.6161 and R2 of 0.9959. RSD and LOD were calculated as 4.2% (n=6) and 1.12×10−9M respectively.
A novel genosensor tranducer was fabricated by modifiying composite GCPE with Gr-Pt hybrid NP. As a result sensitive and selective genosensor was obtained. Display omitted
•Gr–Pt hybrid NP was produced and used for the first time as a part of genosensor transducer.•GCPE was modified with Gr–Pt hybrid NP for the first time.•Gr–Pt hybrid NP/GCPE was used as genosensor transducer for the first time.•More sensitive genosensor was obtained compared to plain and GrOx modified GCPE.
A practical colorimetric assay was developed for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For this purpose, magnetic γ Fe
2
O
3
nanoparticles were synthesized ...and used as a peroxidase-like mimic activity molecule. In the presence of γ Fe
2
O
3
nanoparticles, the color change of H
2
O
2
included 3,3′,5,5′-tetramethylbenzidine was monitored at the wavelength of 654 nm when spike protein interacted with angiotensin-converting enzyme 2 receptor. This oxidation-reduction reaction was examined both spectroscopically and by using electrochemical techniques. The experimental parameters were optimized and the analytical characteristics investigated. The developed assay was applied to real SARS-CoV-2 samples, and very good results that were in accordance with the real time polymerase chain reaction were obtained.
Graphical abstract
We have performed a study on the performance of two microbial glucose sensors based on immobilized
Gluconobacter oxydans
(
G. oxydans
). The first one was prepared by modifying a glassy carbon paste ...electrode (GCPE) containing the microbial cells with graphene oxide (GO), the other one by modifying it with graphene-platinum hybrid nanoparticles (graphene-Pt NPs). The electrode was characterized by following the voltammetric signals of the oxidation of hexacyanoferrate(II) to hexacyanoferrate(III) via the oxidative enzymes contained in
G. oxydans
which convert glucose to gluconic acid. Optimizations were conducted with a conventional GCPE containing
G. oxydans
. After material optimization, the biosensors were applied to the determination of glucose. The linear and analytical ranges for GO based biosensor range from 1 to 75 μM (linear) and 1 to 100 μM (analytical), respectively, with a limit of detection (LOD) of (3 s/m) 1.06 μM (at an S/m of 3). On the other hand, the graphene-Pt hybrid nanoparticle based biosensor showed two linear ranges (from 0.3 to 1 µM and from 1 to 10 μM), a full analytical range from 1 to 50 μM, and an LOD of 0.015 μM. The graphene-Pt hybrid NP based sensors performs better and was applied to the determination of glucose in synthetically prepared plasma samples where it gave recoveries as 101.8 and 104.37 % for two different concentrations. Selectivity studies concerning fructose, galactose, L-ascorbic acid and dopamine were also conducted.
Graphical Abstract
The electrochemical performances of graphene oxide and graphene-platinum hybrid nanoparticle modified
G. oxydans
biosensors were compared.
Influenza is a viral infectious disease considered as a source of many health problems and enormous socioeconomic disruptions. Conventional methods are inadequate for in-field detection of the virus ...and generally suffer from being laborious and time-consuming. Thus, studies aiming to develop effective alternatives to conventional methods are urgently needed. In this work, we developed an approach for the isolation and detection of influenza A virus subtype H9N2. For this aim, two specific influenza receptors were used. The first, anti-matrix protein 2 (M2) antibody, was attached to iron magnetic nanoparticles (MNPs) and used for the isolation of the virus from allantoic fluid. The second biomolecule, Fetuin A, was attached to an electrochemical detectable label, gold nanoparticles (AuNPs), and used to detect the virus tacking advantage from fetuin-hemagglutinin interaction. The MNP-Influenza virus-AuNP formed complex was isolated and treated by an acid solution then the collected gold nanoparticles were deposited onto a screen printed carbon electrode. AuNPs catalyzes the hydrogen ions reduction in acidic medium while applying an appropriate potential, and the generated current signal was proportional to the virus titer. This approach allows the rapid detection of influenza virus A/H9N2 at a less than 16 HAU titer.
•Nanoparticles biosensor for influenza virus type A detection has been demonstrated.•Selective detection of H9N2 via specific antibodies and fetuin-gold nanoparticles.•Featuring high rapidity & sensitivity, small sample volume and a low detection limit.
In this study, an electrochemical approach for the determination of coronavirus disease (COVID-19) was developed. The biosensor system relied on the spike protein (S-protein) based infection ...mechanism of the virus and included separate interactions of receptors like angiotensin-converting enzyme 2 (ACE2) and CD147. After the optimization of experimental parameters, the analytical characteristics of both receptors ACE2 and CD147 were investigated. For ACE2 receptor, the linear detection ranges of the S-protein were found in the range of 700 ng mL
−1
to 1500 ng mL
−1
and from 1500 ng mL
−1
to 7000 ng mL
−1
with a limit of detection (LOD) value of 299.30 ng mL
−1
. Meanwhile, for CD147 receptor the linear range was in the range of 500 ng mL
−1
to 5000 ng mL
−1
with a LOD value of 38.99 ng mL
−1
. After the examination of analytical characteristics, the developed electrochemical approach was applied for severe acute respiratory syndrome coronavirus 2 samples and the obtained results were validated with real time polymerase chain reaction method.
An impedimetric biosensor that was based on SARS-CoV-2 infection mechanism was developed.
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