H2O2 Sensor Research Articles

NOX4 PROTECTIVE EFFECT IN ENDOTHELIAL FUNCTION INVOLVES ACTIVATION OF TRANSIENT RECEPTOR POTENTIAL MELASTATIN 2 (TRPM2) CATION CHANNEL

Objective: Nox4 regulates endothelium-dependent relaxation through production of H2O2, which in turn acts as an EDHF. We demonstrated that TRPM2 is also a target of H2O2 in vascular cells. TRPM2 is a redox-sensitive Ca2+ channel and once activated leads to Ca2 influx. Hypertension-associated endothelial dysfunction involves reduction in eNOS activation and is potentiated in the absence of NOX4. As TRPM2 channel is a H2O2 sensor and regulates Ca2+ entry, we questioned whether impaired vascular relaxation in hypertensive NOX4 KO mice involves the H2O2-TRPM2-Ca2+ axis in endothelial cells. Design and method: WT and TTRhRen hypertensive mice were crossed with Nox4 KO mice. Vascular function was measured by wire myograph in resistance arteries. Ca2+ influx was assessed by fluorescence microscopy in aortic endothelial cells. eNOS activation was assessed by immunoblotting. Results: Blood pressure was significantly increased in TTRhRen (130.3 ± 7.0 mmHg) and TTRhRen/NOX4 KO mice (141.3 ± 18 mmHg) versus control mice (98.1 ± 8.0 mmHg). TTRhRen mice had reduced endothelium-dependent relaxation (Emax: WT 83.5 ± 4.03 vs TTRhRen 59.1 ± 3.5); an effect worsened by NOX4 KO (37.9 ± 5.4), p<0.05. The TRPM2 activator, ADPR, improved vascular relaxation in TTRhRen/NOX4 KO mice (75.9 ± 7.7); an effect recapitulated by H2O2 (74.2 ± 15.4), p < 0.05. Ang II-induced Ca2+ influx in endothelial cells, important in eNOS activation, was reduced by TRPM2 inhibitors (AUC - Ca2+: 8-br-cADPR 76161 ± 1052.0; Olaparib 74763 ± 843.2 and 2-APB 79625 ± 277.4, p < 0.05) and the NOX1/4 inhibitor GKT137831 (AUC - Ca2+: Ang II 107357 ± 1940.2 vs GKT 60270 ± 255.6, p < 0.05). Ang II-induced activation of eNOS (Ser1177) (%: 72.3 ± 24.7) was blocked by GKT137831, PEG-catalase and the TRPM2 inhibitor 8-br-cADPR (p < 0.05). Conclusions: Endothelial dysfunction in TTRhRen mice involves impaired TRPM2 activation. Inhibition/downregulation of Nox4 and reduced bioavailability of H2O2 exacerbates these processes. We identify a novel protective effect of NOX4 in endothelial cells involving H2O2-mediated activation of TRPM2-Ca2+-eNOS signalling.

AQP8 is a crucial H2O2 transporter in insulin-producing RINm5F cells

Peroxiporins are distinct aquaporins (AQP) which, beside water, also facilitate the bidirectional transport of hydrogen peroxide (H2O2) across cellular membranes. H2O2 serves as the major reactive oxygen species that mediates essential cell signaling events. In pancreatic β-cells, H2O2 has been associated with the regulation of cell growth but in excess it leads to failure of insulin secretion, making it important for diabetes mellitus (DM) pathogenesis. In the present study, the role of aquaporin-8 (AQP8) as a peroxiporin was investigated in RINm5F cells. The role of AQP8 was studied in an insulin-producing cell model, on the basis of stable AQP8 overexpression (AQP8↑) and CRISPR/Cas9-mediated AQP8 knockdown (KD). A complete AQP8 knock-out was found to result in cell death, however we demonstrate that mild lentiviral re-expression through a Tet-On-regulated genetically modified AQP8 leads to cell survival, enabling functional characterization. Proliferation and insulin content were found to be increased in AQP8↑ cells underlining the importance of AQP8 in the regulation of H2O2 homeostasis in pancreatic β-cells. Colocalization analyses of V5-tagged AQP8 proteins based on confocal microscopic imaging revealed its membrane targeting to both the mitochondria and the plasma membrane, but not to the ER, the Golgi apparatus, insulin vesicles, or peroxisomes. By using the fluorescence H2O2 specific biosensor HyPer together with endogenous generation of H2O2 using d-amino acid oxidase, live cell imaging revealed enhanced H2O2 flux to the same subcellular regions in AQP8 overexpressing cells pointing to its importance in the development of type-1 DM. Moreover, the novel ultrasensitive H2O2 sensor HyPer7.2 clearly unveiled AQP8 as a H2O2 transporter in RINm5F cells. In summary, these studies establish that AQP8 is an important H2O2 pore in insulin-producing RINm5F cells involved in the transport of H2O2 through the mitochondria and cell membrane and may help to explain the H2O2 transport and toxicity in pancreatic β-cells.

Luminescent NaTb(SO4)2 nanoprobe for hydrogen peroxide based on switchable fluorescence of Tb(IV)/Tb(III) redox couple

The accurate and sensitive detection of hydrogen peroxide (H2O2) is of practical significance in the fields of bioanalysis, medicine, environmental protection as well as food industry. Herein, we design and fabricate NaTb(SO4)2 nanoparticles (NPs) as novel fluorescent nanoprobes for H2O2 detection. The design strategy is based on the fluorescence quenching occurred during the oxidation of Tb(III) to Tb(IV) upon H2O2 addition. The sensing of NaTb(SO4)2 NPs to H2O2 is in a “turn-off” mode, and the sensitivity is tunable by the pH due to the pH-dependence of the oxidizing ability of H2O2. Superior to most of the reported H2O2 sensors, NaTb(SO4)2 NPs exhibit reliable stability in acidic environment and a more sensitive response to H2O2 with a limit of detection (LOD) down to 0.047 μM at pH = 3.2. Based on its high sensitivity and reliable stability, the NaTb(SO4)2 NPs is anticipated to find potential applications in the field of biosensors.

Hydrogen peroxide sensor using the biomimetic structure of peroxidase including a metal organic framework

In this study, hemin that has excellent catalytic activity is adopted as a catalyst component and other materials, such as metal organic framework (MOF) and carbon nanotube (CNT), are further used to alleviate drawbacks of hemin, such as location issue and molecular aggregation. Based on that, a new catalyst consisting of hemin-encapsulated MOF and CNT is developed (Hemin⊂MIL-88-NH2/CNT). To evaluate its catalytic activity, colorimetric and electrochemical evaluations are conducted. When colorimetric method is used, Hemin⊂MIL-88-NH2/CNT shows good catalytic activity due to proper interaction between water media and amine bond of MOF. In electrochemical evaluations, Hemin⊂MIL-88-NH2/CNT has high sensitivity (0.538 μAμM−1cm−2) and low detection limit (0.06 μM) at 0.5–203 μM (R2 = 0.999). Even in amperometric response tests, when 10 μM H2O2 is injected, Hemin⊂MIL-88-NH2/CNT shows a better response than other heme protein- based catalysts ((Hb, Mb and HRP)/CNT) by 2.06–3.26 times. In terms of stability, its catalytic activity is well preserved even under harsh pH and temperature conditions for a long time (89.5% of the initial value after 15 days). With that, it is confirmed that the Hemin⊂MIL-88-NH2/CNT as the catalyst for use in H2O2 sensors is attractive and better than other heme proteins.

Nanostructures in Hydrogen Peroxide Sensing.

In recent years, several devices have been developed for the direct measurement of hydrogen peroxide (HO), a key compound in biological processes and an important chemical reagent in industrial applications. Classical enzymatic biosensors for HO have been recently outclassed by electrochemical sensors that take advantage of material properties in the nano range. Electrodes with metal nanoparticles (NPs) such as Pt, Au, Pd and Ag have been widely used, often in combination with organic and inorganic molecules to improve the sensing capabilities. In this review, we present an overview of nanomaterials, molecules, polymers, and transduction methods used in the optimization of electrochemical sensors for HO sensing. The different devices are compared on the basis of the sensitivity values, the limit of detection (LOD) and the linear range of application reported in the literature. The review aims to provide an overview of the advantages associated with different nanostructures to assess which one best suits a target application.

Synthesis of Silver and Gold Nanoparticles from Rumex roseus Plant Extract and Their Application in Electrochemical Sensors.

The room-temperature synthesis of silver (AgNPs) and gold (AuNPs) nanoparticles from aqueous solution of AgNO3 and HAuCl4 respectively, using Rumex roseus (RR) plant extract as a reducing agent, is reported here for the first time. The nanoparticles obtained were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The formation of nanoparticles with spherical-shaped morphology was verified by TEM and confirmed by UV-Vis spectroscopy through the analysis of Ag and Au plasmon resonance peak and DLS measurements. New electrochemical sensors have been developed by employing the synthesized Ag and Au nanoparticles as modifiers of glassy carbon electrode (GCE) and screen-printed carbon electrode (SPCE), respectively. The AgNPs-modified GCE was investigated for the electrochemical determination of hydrogen peroxide (H2O2). Further enhancement of electrochemical performances was obtained using a nanocomposite made of AgNPs and reduced graphene oxide (rGO)-modified GCE. The AuNPs-SPCE sensor was instead tested in the electrochemical sensing of riboflavin (RF). To our knowledge, this is the first paper reporting Rumex roseus plant extract as a source for the synthesis of metal nanoparticles and their use for developing simple, sensitive and reliable electrochemical sensors for H2O2 and RF.

A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Magnetic Core-Shell Fe3O4@C/Au Nanoparticle Nanocomposite.

Fe3O4@C/Au nanoparticle (AuNP) nanocomposites were prepared through electrostatic adsorption of AuNPs onto PDDA-functionalized core/shell Fe3O4@C magnetic nanospheres, which had been synthesized by a facile solvothermal method. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), etc. Moreover, highly electrocatalytic activity to the reduction of hydrogen peroxide (H2O2) was also exhibited on the Fe3O4@C/AuNP-modified indium tin oxide (ITO) electrode. The effect of solution pH and the modification amount of Fe3O4@C/AuNPs on the performance of electrocatalytic H2O2 reduction was investigated. Under the optimal conditions, the catalytic current showed a linear relationship with the increase of H2O2 concentration in the range of 0.007–15 mM and a detection limit of 5 μM. The H2O2 sensor showed high selectivity for H2O2 detection, which could effectively resist the interference of ascorbic acid (AA), uric acid (UA), and citric acid (CA). Finally, the H2O2 sensor was used in the real fetal bovine serum to detect H2O2 and obtained satisfactory results with the recovery values ranging from 95.14 to 103.6%.

Electrochemical behavior of CuO/rGO nanopellets for flexible supercapacitor, non-enzymatic glucose, and H2O2 sensing application

In the present article, graphene oxide (GO) sheets and monoclinic copper oxide (CuO) nanocrystals are connected with each other and result in the formation of CuO/rGO nanopellets, and these nanopellets synthesized using coprecipitation method. The nanopellet structured CuO/rGO composite on carbon cloth, which act as current collector exhibits specific capacitance of 188 F g−1 at a current density of 0.2 A g−1 and up to 96.3% capacity retention after 2000 charge-discharge cycles. It shows a maximum energy density of 7.32 Wh kg−1 and power density of 53 W kg−1. The glucose sensing characteristics of CuO/rGO nanopellet is investigated on carbon cloth and ITO substrate. It shows glucose sensitivity of 0.805 mA mM−1 cm−2 and 0.2982 mA mM−1 cm−2 for a bundle like structured CuO/rGO composite on carbon cloth and ITO substrate, respectively. Further H2O2 sensing is studied on ITO substrate, which manifests H2O2 sensitivity of 84.39 μA mM−1 cm−2. The results indicate that nanopellet structured CuO/rGO composite could be a promising electrode material for supercapacitor, glucose, and H2O2 sensor.

Paper‐Based, Chemiresistive Sensor for Hydrogen Peroxide Detection

AbstractDetecting hydrogen peroxide (H2O2) as the side product of enzymatic reactions is of great interest in food and medical applications. Despite the advances in this field, the majority of reported H2O2 sensors are bulky, expensive, limited to only one phase detection (either gas or liquid), and require multistep fabrications. This article aims to address some of these limitations by presenting a 3D printable paper‐based sensor made from poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) decorated with horseradish peroxidase, an enzyme able to interact with H2O2. Unlike most electrochemical PEDOT:PSS‐based H2O2 sensors with voltametric or potentiometric mechanisms, the sensing mechanism in this technology is impedimetric, significantly simplifying the fabrication process. Here, the resistance of sensors proportionally changes with H2O2 concentration upon exposure to liquid or gas with a linear trend within the range of 61.3 × 10−9 and 61.3 × 10−6 m H2O2. The observed correlation between the resistance and H2O2 concentration is highly dependent on the level of integrated enzyme, suggesting the direct contribution of horseradish peroxidase in the co‐redoxing of PEDOT:PSS in the presence of H2O2. Raman and UV–vis spectroscopies also confirm the structural change of PEDOT in the presence of H2O2 which is facilitated by the enzyme.

Hydrogen peroxide concentration measurement by an enzymatic/holographic hybrid structured sensor with polarized spectrometry

In order to increase the measuring range and resolution of hydrogen peroxide concentration, fabrication of an enzymatic/holographic hybrid structured hydrogen peroxide sensor and the polarized spectrometry were proposed. The hybrid structured H2O2 sensor consisted of an enzymatic sensing film and a holographic plate. Diffraction gratings recorded by holographic plate provided first order wavelength separation and specificity enzyme reacted with H2O2. Smaller grating pitch of sensor exhibited a narrower wavelength bandwidth selection of light source that can be enhanced stability and resolution of the proposed system. Furthermore, the results showed that the measurement range of the H2O2 concentration would be larger of the measurement with polarized light. The results showed that the measurement range of H2O2 concentration could cover 10−5% to 10-2% with the hybrid structured H2O2 sensor. The results also indicated that use of horizontal polarized light to measure the H2O2 concentration exhibited high measurement sensitivity with value of 8043 (photon counts/%) and the optimum resolution of proposed method can be better than 3.3 × 10-6% (0.033 ppm).

Surface Plasmon Resonance Field-Enhanced Fluorescence Properties of Gold Quantum Dots on Polyelectrolyte Multilayers and Their H2O2 Sensor Application

In this work, we investigate surface plasmon field-enhanced fluorescence (SPF) emission from gold quantum dots (AuQDs) on a polyelectrolyte multilayer ultrathin film deposited onto an Al thin film. Polyelectrolyte layers of poly(diallyl dimethyl ammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS) are deposited onto the Al surface using a layer-by-layer (LbL) adsorption technique. AuQDs are subsequently deposited onto the PDADMAC/PSS ultrathin films to study their fluorescence enhancement/quenching phenomenon, as monitored by SPF spectroscopy. The distance between the AuQDs and the Al thin film is controlled by the number of deposited PDADMAC/PSS LbL films. With increasing number of the PDADMAC/PSS bilayers, the fluorescence intensity of the AuQDs increases until the optimum distance between the AuQDs and Al layers is achieved. Moreover, silver nanoprisms (AgNPrs) are coated onto the AuQDs for H2O2 sensing. When the AgNPrs are present, a decrease in the fluorescence intensity of the AuQDs due to energy transfer from the AuQDs to the AgNPrs is observed. Recovery of the fluorescence intensity of the AuQDs is observed upon injection of a H2O2 solution, where the recovery of the intensity is proportional to the H2O2 concentration in the range from 1 pM to 100 nM and results from the oxidation reaction or etching of the AgNPrs. The fluorescence recovery is attributed to weakening of the quenching effect by a reduction in concentration of the AgNPrs. The proposed system exhibits strong potential for the development of H2O2 sensors.

Gold Nanowires – Assisted Prussian Blue Enhancing Peroxidase – Like Activity for the Non‐enzymatic Electrochemically Sensing H2O2 Released From Living Cells

AbstractPrussian blue nanoparticles (PBNPs) have peroxidase‐like activity for H2O2. However, PB alone have poor electrochemical performances. Herein, a strategy was proposed by direct in‐situ growth PBNPs onto gold nanowires (AuNWs) surface to obtain the peroxidase‐like activity with about 4.05 times higher than that of PBNPs alone. PBNPs@AuNWs was employed to construct a non ‐ enzymatic electrochemical H2O2 sensor with the detection limit of 5.3×10−9 mol/L (S/N=3). The sensor was successfully used to detect H2O2 in human serum samples or secreted from living HeLa cells. It may be a competitive candidate for H2O2 assaying in biological samples or cellular investigation.

A Nonenzymatic Hydrogen Peroxide Electrochemical Sensing and Application in Cancer Diagnosis.

The diagnosis of malignant tumors is essential for informing clinical decisions regarding therapeutic options. Current imaging and pathological diagnostic methods do not provide quantitative molecular information that is important in tumor identification. Moreover, pathological tissue analysis is dependent on unevenly distributed pathological features. The tumor microenvironment has been documented to have hydrogen peroxide (H2 O2 ). This study presents a biologically sensitive and efficient H2 O2 electrochemical sensor based on PtNi nanoparticle-doped N-reduced graphene oxide (PtNi-N-rGO) with a low detection limit (2.8× 10-9 m), a fast response time (<6 s) and desirable anti-interference characteristics. Herein, H2 O2 is used as molecular biomarker. The sensor successfully captures H2 O2 from cancer cells. In addition, it efficiently detects tumor tissues, adjacent tissues, and normal tissues. This study demonstrates the H2 O2 sensor potential to rapidly detect tumor tissues. This technique provides a complementary method for pathological tumor diagnosis that is independent of the traditional pathology labs.

Expanding Horizon: Controllable Morphology Design of an Ecofriendly Tamarind Seedcase-Derived Porous Carbonaceous Biomass as a Versatile Electrochemical Biosensor Platform for Reactive Oxygen Species

Novel, uniform, and ordered biomass carbon materials using the skin tissue of tamarind seedcase (TS) as the carbon source were first synthesized by one-step carbonization or hydrothermal carbonization (HTC) without being template-assisted and are further explored for highly sensitive H₂O₂ biosensing. The results demonstrated that the obtained biomass carbonaceous materials (TS-C, TS powder (TSP), TSP-C, TS-HTC, and TSP-HTC) with obviously different morphologies, absorption characteristics, and pore size distributions showed variable electrocatalytic properties. TS-HTC with promising pitaya flower-like structures and a high specific surface area of 436.425 m² g–¹ presented the optimized catalytic performance for H₂O₂ detecting at the peak potential of −0.38 V. The corresponding H₂O₂ sensor displayed an outstanding sensitivity of 122.02 μA mM–¹ cm–² at the H₂O₂ concentration range of 0.05–0.5 mM and 80.79 μA mM–¹ cm–² (0.5–2.7 mM), respectively. The response time was short at 3.61 s, indicating that TS-HTC has turned out to be an attractive material for designing H₂O₂ biosensors, with a promising internally interlinked reticulate-like structure for capturing biomolecules. Moreover, the direct detection of H₂O₂ released from Hep3B cells is demonstrated on TS-HTC-based sensors, being effective to detect H₂O₂ activity in situ for the early diagnosis of liver cancer, suggesting its potential application for efficient recognition and determination of H₂O₂ in fields of life science, clinics, disease prevention, and so on.

One-step synthesis of γ-Fe2O3/Fe3O4 nanocomposite for sensitive electrochemical detection of hydrogen peroxide

Maghemite/magnetite nanocomposite (γ-Fe2O3/Fe3O4) was prepared via an electrochemical method using pulse alternating current and applied for electrocatalytic reduction and sensing of hydrogen peroxide. The structural and compositional analysis of the γ-Fe2O3/Fe3O4 was characterized by XRD, SEM, TEM and XPS. Its thermal decomposition behavior was studied using TG/DSC. The mechanism for γ-Fe2O3/Fe3O4 nanocomposite formation was proposed. Furthermore, the H2O2 sensing performance of the γ-Fe2O3/Fe3O4 nanocomposite was evaluated in 0.1 M KH2PO4. The sensor exhibited a fast electron transfer process in γ-Fe2O3/Fe3O4 nanocomposite. The optimized H2O2 sensor revealed a remarkable low limit of detection of 0.05 μM, a wide linear range from 0.0002 to 8 mM, and a fast response time of 2 s. These results demonstrated that γ-Fe2O3/Fe3O4 prepared via an electrochemical method using pulse alternating current is a promising efficient material for electrochemical sensing of H2O2.

A high-performance photoelectrochemical sensor for the specific detection of H2O2 and glucose based on an organic conjugated microporous polymer

A photoelectrochemical sensor for H2O2 and glucose with remarkable specificity is developed based on a unique periodic D–A type PorPc-CMP hollow tube.

Recent advances in enzyme-free electrochemical hydrogen peroxide sensors based on carbon hybrid nanocomposites

The article gives an overview of the recent advances of the enzyme-free electrochemical H2O2 sensors based on carbon hybrid nanocomposites in the hope of suggesting feasible approaches to further enhance the sensitivity of carbon hybrid materials.

Cu/Electrochemically reduced graphene oxide layered nanocomposite for non-enzymatic H2O2 sensor

In this present study, we modified the Au surface with nanocomposite containing Cu nanoparticles and electrochemically reduced graphene oxide (ERGO) to increase the electrocatalytic performance of Au electrode for nonenzymatic amperometric detection of H2O2. The morphology and structural properties of the Cu/ERGO nanocomposites were investigated by XPS, XRD, STM and SEM techniques. The Cu/ERGO nanocomposite electrode displayed good performance for the electrochemical detection of H2O2, compared to naked Au and Cu-modified Au electrodes, in terms of low working potential (at around −0.2 V), high sensitivity (20 μA cm−2 mM−1), and low detection limit (1.87 × 10−9 mol.L−1).

Electrochemical sensor based on the Mn3O4/CeO2 nanocomposite with abundant oxygen vacancies for highly sensitive detection of hydrogen peroxide released from living cells.

Based on the strategy of increasing the number of oxygen vacancies to improve the catalytic performance, we have developed a novel electrochemical sensor based on the multivalent metal oxides cerium dioxide and manganous oxide (Mn3O4/CeO2) for reliable determination of extracellular hydrogen peroxide (H2O2) released from living cells. The Mn3O4/CeO2 nanocomposite was characterized by high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical performance of the Mn3O4/CeO2 nanocomposite modified glassy carbon electrode (Mn3O4/CeO2/GCE) was investigated. Owing to the abundant oxygen vacancies and strong synergistic effect between the multivalent Ce and Mn, the sensor exhibited excellent catalytic activity and selectivity for the electrochemical detection of H2O2 with a low quantitation limit of 2 nM. Moreover, Mn3O4/CeO2/GCE exhibited excellent reproducibility, repeatability, and long-term storage stability. Because of these remarkable analytical advantages, the constructed sensor was able to determine H2O2 released from living cells with satisfactory results. The results showed that the Mn3O4/CeO2 sensor is a promising candidate for a nanoenzymatic H2O2 sensor with the possibility of applications in physiology and diagnosis.

Silver cluster (Ag6) decorated coronene as non-enzymatic sensor for glucose and H2O2

Silver-graphene quantum dots are promising electrochemical sensors due to their unique electronic properties. Herein, we report the comprehensive DFT study to explore the electronic properties of silver cluster (Ag6) decorated coronene as model for silver graphene quantum dots. The current study aims to investigate the sensing ability of silver-coronene complex for non-enzymatic electrochemical detection of glucose & H2O2. The stability of the complexes of analytes with silver decorated coronene is supported by their greater interaction energies (−36.7 to −44.9 kcal mol−1). NBO charge analysis and charge decomposition analysis (CDA) reveal donor-acceptor charge transfer interactions in the complexes. Frontier molecular orbital analysis illustrates that charge is transferred from analytes to silver decorated coronene during excitation from HOMO to LUMO. The Uv–visible results show that λmax is red shifted during interactions of analytes with silver decorated coronene. The NCI analysis illustrates the strong non-covalent (M … O) and unusual M … H–O interactions in the complexes. The precedent sensing performance of Ag6-coronene might be attributed to the synergistic effect of both silver clusters and coronene in the composite. The evaluated results validate the excellent sensing ability of silver-graphene quantum dots for the detection of glucose & H2O2. The outcome of the current study and its prospects will open the avenue for the rational development of smart sensors.