Fabrication of Electrochemical Biosensor Using Zinc Oxide Nanoflowers for the Detection of Uric Acid

Author(s):  
priyanka dutta ◽  
Vikas sharma ◽  
Hema bhardwaj ◽  
ved varun agrawal ◽  
Rajesh nil ◽  
...  

Abstract A label-free electrochemical biosensor has been developed using Zinc Oxide nanoflowers (ZnONFs) for the detection of Uric acid. ZnONFs have been synthesized by hydrothermal process and characterized with several techniques such as Ultraviolet-Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR) study, X-ray diffraction study, Raman spectroscopy, Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy (HR-TEM) and electrochemical analyser to confirms the formation of nanoflowers and fabrication of electrode and bioelectrodes for uric acid detection. Pure and uniform needle flowers and deposited onto Indium Tin Oxide (ITO) substrate through electrophoretic deposition technique. Further, electrochemical studies have been performed with immobilized enzymatic bioelectrode followed by various uric acid concentrations. It has been found that the fabricated biosensor shows high sensitivity (10.38 µA/ mg/mL /cm2) and a limit of detection of 0.13 mg/mL in the range of 0.005 to 1.0 mg/mL. This study demonstrates the potential use of ZnONFs for the construction of overly sensitive biosensors for Uric acid detection.

Author(s):  
Peihong Deng ◽  
Jinxia Feng ◽  
Jingyun Xiao ◽  
Yanping Wei ◽  
Jinsong Zuo ◽  
...  

Abstract High levels of uric acid (UA) in the human body usually cause diabetes, hypertension and atherosclerosis, kidney diseases, and neurological diseases. Hence, it is important to develop sensitive methods for UA determination. In this paper, nanocomposite composed of ceria nanoparticles and reduced graphene was successfully modified on the surface of glassy carbon electrode (ceria NPs-rGO/GCE) by a simple electroreduction method. The morphology, structure and property of the ceria NPs-rGO/GCE was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrocatalytic activity of the ceria NPs-rGO/GCE for uric acid (UA) oxidation was studied in detail. The results showed that the ceria NPs-rGO/GCE exhibited excellent selectivity and high sensitivity for UA detection. In 0.05 M H2SO4 solution, a linear range of 0.02-20 M and a low detection limit of 8.0 nM of UA were obtained on the ceria NPs-rGO/GCE. This developed method was successfully applied for the detection of UA in human serum and urine samples, and its recoveries reached 95.8%-105.0%.


2020 ◽  
Vol 13 (05) ◽  
pp. 2041004 ◽  
Author(s):  
Yang Li ◽  
Yanxian Guo ◽  
Binggang Ye ◽  
Zhengfei Zhuang ◽  
Peilin Lan ◽  
...  

Two-dimensional (2D) nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features. Herein, 2D hafnium ditelluride (HfTe[Formula: see text], a new member of transition metal tellurides, is exploited to support gold nanoparticles fabricating HfTe2-Au nanocomposites. The nanohybrids can serve as novel 2D surface-enhanced Raman scattering (SERS) substrate for the label-free detection of analyte with high sensitivity and reproducibility. Chemical mechanism originated from HfTe2 nanosheets and the electromagnetic enhancement induced by the hot spots on the nanohybrids may largely contribute to the superior SERS effect of HfTe2-Au nanocomposites. Finally, HfTe2-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bacteria, which realize the rapid and ultrasensitive Raman test of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to [Formula: see text]. Combined with principal component analysis, HfTe2-Au-based SERS analysis also completes the bacterial classification without extra treatment.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2577 ◽  
Author(s):  
Yuanying Liang ◽  
Ting Guo ◽  
Lei Zhou ◽  
Andreas Offenhäusser ◽  
Dirk Mayer

The detection of chemical messenger molecules, such as neurotransmitters in nervous systems, demands high sensitivity to measure small variations, selectivity to eliminate interferences from analogues, and compliant devices to be minimally invasive to soft tissue. Here, an organic electrochemical transistor (OECT) embedded in a flexible polyimide substrate is utilized as transducer to realize a highly sensitive dopamine aptasensor. A split aptamer is tethered to a gold gate electrode and the analyte binding can be detected optionally either via an amperometric or a potentiometric transducer principle. The amperometric sensor can detect dopamine with a limit of detection of 1 μM, while the novel flexible OECT-based biosensor exhibits an ultralow detection limit down to the concentration of 0.5 fM, which is lower than all previously reported electrochemical sensors for dopamine detection. The low detection limit can be attributed to the intrinsic amplification properties of OECTs. Furthermore, a significant response to dopamine inputs among interfering analogues hallmarks the selective detection capabilities of this sensor. The high sensitivity and selectivity, as well as the flexible properties of the OECT-based aptasensor, are promising features for their integration in neuronal probes for the in vitro or in vivo detection of neurochemical signals.


Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 105
Author(s):  
Selma Rabai ◽  
Ahlem Teniou ◽  
Gaëlle Catanante ◽  
Messaoud Benounis ◽  
Jean-Louis Marty ◽  
...  

Cadmium (Cd2+) is one of the most toxic heavy metals causing serious health problems; thus, designing accurate analytical methods for monitoring such pollutants is highly urgent. Herein, we report a label-free electrochemical aptasensor for cadmium detection in water. For this, a nanocomposite combining the advantages of gold nanoparticles (AuNPs), carbon nanotubes (CNTs) and chitosan (Cs) was constructed and used as immobilization support for the cadmium aptamer. First, the surface of a glassy carbon electrode (GCE) was modified with CNTs-CS. Then, AuNPs were deposited on CNTs-CS/GCE using chrono-amperometry. Finally, the immobilization of the amino-modified Cd-aptamer was achieved via glutaraldehyde cross-linking. The different synthesis steps of the AuNPs/CNTs/CS nano assembly were characterized by cyclic voltammetry (CV). Electrochemical impedance spectroscopy (EIS) was employed for cadmium determination. The proposed biosensor exhibited excellent performances for cadmium detection at a low applied potential (−0.5 V) with a high sensitivity (1.2 KΩ·M−1), a detection limit of 0.02 pM and a wide linear range (10−13–10−4 M). Moreover, the aptasensor showed a good selectivity against the interfering ions: Pb2+; Hg2+ and Zn2+. Our electrochemical biosensor provides a simple and sensitive approach for Cd2+ detection in aqueous solutions, with promising applications in the monitoring of trace amounts of heavy metals in real samples.


2019 ◽  
Vol 19 (6) ◽  
pp. 3637-3642 ◽  
Author(s):  
Yas Al-Hadeethi ◽  
Ahmad Umar ◽  
Kulvinder Singh ◽  
Ahmed A Ibrahim ◽  
Saleh. H Al-Heniti ◽  
...  

Herein, we report the synthesis, characterization and picric acid chemical sensing application of samarium (Sm) doped ZnO nanorods. The Sm-doped ZnO nanorods were synthesized by facile hydrothermal process and characterized using various analytical methods which confirmed the large-scale synthesis and wurtzite hexagonal crystal structure for the synthesized nanorods. The doping of Sm ions in the lattices of the synthesized nanorods was evaluated by the energy dispersive X-ray spectroscopy (EDS). The synthesized Sm-doped ZnO nanorods were used as potential scaffold to fabricate high sensitive and reproducible picric acid chemical sensor based on I–V technique. The fabricated picric acid chemical sensor based on Sm-doped ZnO nanorods exhibited a high sensitivity of 213.9 mA mM−1 cm−2 with the limit of detection of ∼0.228 mM and correlation coefficient of R═0.9889. The obtained results revealed that the facile grown Sm-doped ZnO nanorods can efficiently be used to fabricate high sensitive and reproducible chemical sensors.


Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 84 ◽  
Author(s):  
Aihua Jing ◽  
Gaofeng Liang ◽  
Yixin Yuan ◽  
Wenpo Feng

The quantification of ascorbic acid (AA), dopamine (DA), and uric acid (UA) has been an important area of research, as these molecules’ determination directly corresponds to the diagnosis and control of diseases of nerve and brain physiology. In our research, graphene oxide (GO) with nano pores deposited with gold nanoparticles were self-assembled to form three-dimensional (3D) Au/holey-graphene oxide (Au/HGO) composite structures. The as-prepared 3DAu/HGO composite structures were characterized for their structures by X-ray diffraction, Raman spectrum, scanning electron microscopy, and transmission electron microscopy coupled with cyclic voltammograms. Finally, the proposed 3DAu/HGO displayed high sensitivity, excellent electron transport properties, and selectivity for the simultaneous electrochemical determination of AA, DA and UA with linear response ranges of 1.0–500 μM, 0.01–50 μM and 0.05–50 μM respectively. This finding paves the way for graphene applications as a biosensor for detecting three analytes in human serum.


2018 ◽  
Vol 25 (Supp01) ◽  
pp. 1840004 ◽  
Author(s):  
W. KOETNIYOM ◽  
P. SOMBOONSAKSRI ◽  
J. PRASOBCHOKCHAIKUN ◽  
S. KALASUNG ◽  
N. NUNTAWONG ◽  
...  

In this study, surface-enhanced Raman spectroscopic (SERS) substrates with reusability were carefully fabricated and investigated. Based on a simple and cost-effective hydrothermal process, zinc sheets were used as a base for growing zinc oxide nanorods (ZnO NRs) with hexagonal structures as templates for the SERS substrates. In the experimentation, the authors explored a variation of the physical NR structures based on precursors of zinc nitrate (Zn(NO[Formula: see text]: hexamethylenetetramine (HMTA) at 1:1 ratio, in aqueous solution with DI water at a concentration of 2.5–20[Formula: see text]mM. The prepared zinc oxide templates were finally decorated with gold nanoparticles (Au NPs) with the sputtering deposition for 90[Formula: see text]s in order to promote the SERS-active surface. From physical observations, the scanning electron microscopic (SEM) results showed that the ZnO NRs exhibited an increase in size from 56.4[Formula: see text]nm to 244.06[Formula: see text]nm as the solution concentration was increased. Further investigations also demonstrated that the Au-decorated SERS-active samples had the gold nanoparticles covering the top of the ZnO NRs. The prepared SERS substrates were finally measured for the Raman enhancement with methylene blue (MB) as the test molecules. The results showed that the SERS substrates could detect the Raman peaks of the MB at the limit of detection of [Formula: see text][Formula: see text]M. In addition, the SERS substrates were tested for reusability with the UV exposure, up to at least nine cycles. This work therefore reported the progress of the fabrications of the SERS-active materials with the reusable potentials in several SERS applications.


Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 103
Author(s):  
Abbas Panahi ◽  
Deniz Sadighbayan ◽  
Saghi Forouhi ◽  
Ebrahim Ghafar-Zadeh

Field-effect transistor (FET) biosensors have been intensively researched toward label-free biomolecule sensing for different disease screening applications. High sensitivity, incredible miniaturization capability, promising extremely low minimum limit of detection (LoD) at the molecular level, integration with complementary metal oxide semiconductor (CMOS) technology and last but not least label-free operation were amongst the predominant motives for highlighting these sensors in the biosensor community. Although there are various diseases targeted by FET sensors for detection, infectious diseases are still the most demanding sector that needs higher precision in detection and integration for the realization of the diagnosis at the point of care (PoC). The COVID-19 pandemic, nevertheless, was an example of the escalated situation in terms of worldwide desperate need for fast, specific and reliable home test PoC devices for the timely screening of huge numbers of people to restrict the disease from further spread. This need spawned a wave of innovative approaches for early detection of COVID-19 antibodies in human swab or blood amongst which the FET biosensing gained much more attention due to their extraordinary LoD down to femtomolar (fM) with the comparatively faster response time. As the FET sensors are promising novel PoC devices with application in early diagnosis of various diseases and especially infectious diseases, in this research, we have reviewed the recent progress on developing FET sensors for infectious diseases diagnosis accompanied with a thorough discussion on the structure of Chem/BioFET sensors and the readout circuitry for output signal processing. This approach would help engineers and biologists to gain enough knowledge to initiate their design for accelerated innovations in response to the need for more efficient management of infectious diseases like COVID-19.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Médéric Loyez ◽  
Mathilde Wells ◽  
Stéphanie Hambÿe ◽  
François Hubinon ◽  
Bertrand Blankert ◽  
...  

Abstract Background Early malaria diagnosis and its profiling require the development of new sensing platforms enabling rapid and early analysis of parasites in blood or saliva, aside the widespread rapid diagnostic tests (RDTs). Methods This study shows the performance of a cost-effective optical fiber-based solution to target the presence of Plasmodium falciparum histidine-rich protein 2 (PfHRP2). Unclad multimode optical fiber probes are coated with a thin gold film to excite Surface Plasmon Resonance (SPR) yielding high sensitivity to bio-interactions between targets and bioreceptors grafted on the metal surface. Results Their performances are presented in laboratory conditions using PBS spiked with growing concentrations of purified target proteins and within in vitro cultures. Two probe configurations are studied through label-free detection and amplification using secondary antibodies to show the possibility to lower the intrisic limit of detection. Conclusions As malaria hits millions of people worldwide, the improvement and multiplexing of this optical fiber technique can be of great interest, especially for a future purpose of using multiple receptors on the fiber surface or several coated-nanoparticles as amplifiers.


2011 ◽  
Vol 194-196 ◽  
pp. 429-435
Author(s):  
Wen Zhang ◽  
Yong Ning He ◽  
Wu Yuan Cui ◽  
Cheng Bo Zhou

Three different kinds of zinc oxide (ZnO) nanostructure films have been synthesized on an indium tin oxide (ITO) glass substrate by electrochemical method with adjusting the concentration of the electrolyte, deposition time and temperature. X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and photoluminescence (PL) spectrum have been used to determine the characteristics of these nanostructures. The results show that concentration of the electrolyte is one of the most important factors that determine the morphologies of ZnO films. Nanobuds, nanorods, flakes are obtained with the electrolyte concentration increasing. Nanobuds and nanorods have no significant changes with the deposition time prolonged while the flakes grow bigger and thicker. The flakes merge together at high temperature while nanobuds remain unchanged except getting larger and sparser. Nanobuds and nanorods show single crystal patterns while the flakes are composted by multi crystals. The reasons forming such different morphology were discussed according to crystal growth theory. The PL spectra of these ZnO films are quite different according to various microstructures. The film with flake structure has a significant widen near edge emission peak with the depressed visible emission, which may have potential applications on optoelectronic devices and sensors.


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