Oxide Nanorods Research Articles

Gd(III)-Doped ZnO Nanorods on Chalcogenide-Modified Graphene for Enhanced Voltammetric Detection of Methyl Carbamate

Ronidazole (RNZ) is an essential veterinary antibiotic with potential carcinogenic effects. It can persist in the environment, contaminating water sources and entering the human food chain, posing significant health risks. Hence in this study, we synthesized gadolinium-doped zinc oxide (Gd@ZnO) nanorods embedded in sulfur-doped reduced graphene oxide (S-rGO) nanocomposite-based electrochemical sensor, designed to address these concerns. Furthermore, the as-prepared samples were characterized and analyzed using various analytical techniques. As per voltammetric result our proposed Gd@ZnO/S-rGO sensor demonstrates excellent LOD (0.0071 μM, 0.0023 μM), exceptional sensitivity (0.9270 μA μM–1 cm–2, 0.4941 μA μM–1 cm–2) and selectivity towards RNZ, with a wide linear range of detection (0.001 μM - 576.18 μM and 0.001 μM – 438.80 μM). Its efficacy in practicable applicability is further validated through testing with biological (bovine and chicken meat serum) and environmental samples (river water), demonstrating a satisfactory recovery rate of 97 to 101 %. All of the study’s findings show that the proposed sensor’s application is targeted toward monitoring RNZ in environmental water samples and food products, ensuring regulatory compliance and safeguarding public health.

Enhanced ePAD-DNA biosensor incorporating ZnO-NRs: Rapid and reliable electrochemical detection of field-isolated Pasteurella multocida

An electrochemical sensor has received much attention due to its importance for early infection identification, hinting at its critical relevance in diagnostic applications. For the detection of field-isolated strains of Pasteurella multocida, this paper reports the development and fabrication of a DNA-based electrochemical biosensor by integrating zinc oxide (ZnO) nanorods (NRs) into an electrochemical paper-based analytical device (ePAD). One significant improvement over the state-of-the-art features of the sensor is the using paper, an economically viable substrate that can be manufactured in large numbers. These sensors, being categorized under precision instruments with an ecologically friendly design, are ideal for mass production of eco-sensitive substrates. The biosensor is more sensitive and specific as compared to the conventional PCR-based sensing techniques. Moreover, the biosensor exploits the inherent properties of ZnO-NRs to amplify the signal output, whereas ePAD limits detection cost. In addition, a probe targeting the KMT gene of P. multocida was first characterized using conventional PCR and then immobilized onto the ZnO nanorods-modified ePAD surface, which improved the biosensor's ability for the rapid and selective genetic material of the pathogen detection. In addition, the sensor was validated using the methods of Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV). The reported biosensor it provides Linear Response of 0.001-10 μg/ml with LOD 0.001 μg/ml within a response time of 30 s. Subsequently, the biosensor reveals fast kinetics of the reaction as a powerful tool for timely and accurate diagnostics, pointing to its contribution to further development in biosensing technologies in the diagnostic area of infectious diseases at hospitals and clinics.

Z-Scheme Enabled 1D/2D Nanocomposite of ZnO Nanorods and Functionalized g-C3 N4 Nanosheets for Sustainable Degradation of Terephthalic Acid.

The urgent need to mitigate water pollution and achieve Sustainable Development Goal 14 (SDG 14)-Life below water, necessitates developing efficient and eco-friendly wastewater treatment technologies. This research addresses this challenge by photocatalytic degradation of terephthalic acid, a precursor for PET bottles using environment-friendly and biocompatible photocatalysts. The 1D/2D nanocomposite comprising zinc oxide (ZnO) nanorods and functionalized graphitic carbon nitride (Zn-TG) nanosheets were synthesized and thoroughly characterized. The nanocomposite effectively mitigated the individual drawbacks of Zn-TG agglomeration and the wide band gap of ZnO as confirmed through zeta potential and Tauc's plot studies, respectively. The synthesized nanocomposite achieved ~100 % degradation within 60 minutes, exhibiting superior kinetics (~2.5 times) compared to pristine samples. The enhanced degradation efficiency was elucidated by efficient charge carrier transfer (~5 times faster) and separation (~2 times improved) as confirmed through electrochemical impedance spectroscopy and time-resolved photoluminescence studies. The proposed Z-scheme pathway provides mechanistic insights. This proposed mechanism is supported by extensive electron paramagnetic resonance (EPR) and scavenger studies. The liquid chromatography-mass spectrometry (LC-MS) analysis confirms the formation of less toxic byproducts for ensuring that the wastewater treatment process is efficient and environmentally friendly. This research helps in developing a highly effective and sustainable wastewater treatment technology.

Single-step hydrothermal synthesis of zinc oxide nanorods for potential use as nano-antibiotics without seeding or bases.

The alarming global rise in antibiotic resistance, driven by the widespread overuse of traditional antibiotics, has created an urgent demand for new antimicrobial solutions. This study presents zinc oxide (ZnO) nanorods as a potential nano-antibiotic agent. ZnO nanorods, with a 2:3 aspect ratio, were synthesized using an efficient one-step hydrothermal method at a low temperature of 100°C, reducing the synthesis time to just 5 hours. The synthesized ZnO nanorods' morphology, structure, and composition were characterized using scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy. The potent antimicrobial activity of these nanorods against common bacterial strains such as Escherichia coli, Bacillus subtilis, and Vibrio parahaemolyticus was examined through optical density at 600 nm (OD600) measurements and inhibition zone analysis, demonstrating substantial inhibition of bacterial growth. In particular, at a concentration of 5 mg/mL, ZnO nanorods achieved a 96% reduction of B. subtilis bacteria in OD600 and an impressive 99.87% reduction in culturing assays within one day, showcasing bactericidal efficiency on par with tetracycline at 0.003 mg/mL. Furthermore, a predictive model of bacterial growth was developed and validated, providing insights into the time-dependent bactericidal efficiency of the synthesized nanorods. These results highlight the potential of ZnO-based composites as a promising solution to combat antibiotic resistance, paving the way for next-generation antimicrobial materials.

UV light-triggered fluorescence corrosion sensing coatings for AA2024-T3 based on 8-hydroxyquinline loaded vanadium oxide nanorods

Fluorescent corrosion indicators potentially locate the underlying corrosion on metallic substrates based on sensing metal ions caused by corrosion reactions. Nanoparticles loaded with indicators are significant components of the fluorescence corrosion detection system. These fluorescent coatings face challenges (including fluorescence quenching, sluggish response rate, and expensive instrumentation). To tackle such issues, we have developed 8-hydroxyquinoline (8-HQ) loaded oxygen-deficient vanadium oxide (VOx) nanorods (∼220 nm in length and ∼50 nm in width) via solvothermal technique yielding enhanced fluorescence efficiency. 8-HQ/VOx/Ac2403 was utilized to develop a fluorescent corrosion sensing coating for AA2024-T3. The system is designed to detect corrosion within the first few days to weeks after exposure to corrosive conditions by making a complex by reacting with metal ions (Al3+), resulting in a reduction and bright blueish fluorescence effect in the exposure of UV light and can be seen with the naked eye. As a result, fluorescent corrosion-sensing coatings provide a practical substitute for typical coatings to satisfy rising industrial demands by providing corrosion sensing before significant structural damage occurs.

Unveiling the importance of controllable growth of c-axis oriented Sn-doped ZnO nanorod arrays: towards humidity sensing applications

In this study, tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (SZO) were prepared using a sonication assisted sol-gel immersion method, with the growth of the nanorod arrays controlled by varying the immersion time in the precursor material. Morphology images taken using a Field Emission Scanning Electron Microscope (FESEM) demonstrated an enlargement of the average diameter of the nanorod arrays from 55 nm at 5 min immersion to 122 nm at 200 min immersion. The cross-sectional and surface elemental analysis showed that the sample immersed for 60 min has the highest detection of Sn, with a bulk concentration of 1.8 at.% and surface concentration of 1 at.%. Interestingly, we noticed that Sn is not exist on the surface of 200 min immersion, indicating the depletion of the Sn precursor due to the prolongation of the immersion time. From the current voltage (I-V) analysis, 60 min immersion sample generated the lowest thin film resistivity, which engendered the best humidity sensitivity of 4.05. This study demonstrated the significant importance of optimizing the immersion or growth time for doped 1-D nanostructures to obtain the best humidity sensing performance.

Nanocomposite superstructure of zinc oxide mesocrystal/reduced graphene oxide with effective photoconductivity

Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure, which have potentially tunable optical, electronic, and electrical properties suitable for practical applications. Herein, we report an effective method for synthesizing mesocrystal zinc oxide nanorods (ZnONRs). The crystal, surface, and internal structures of the zinc oxide mesocrystals were fully characterized. Mesocrystal zinc oxide nanorods/reduced graphene oxide (ZnONRs/rGO) nanocomposite superstructure were synthesized also using the hydrothermal method. The crystal, surface, chemical, and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized. The optical absorption coefficient, bandgap energy, band structure, and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties. Finally, the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet (UV) photodetection applications. Finally, we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.

Integration of ZnO‐Ag Nanocomposites into PMMA Thin Film for Enhanced Antibacterial Applications

AbstractThe exploration of advanced materials has become imperative for addressing challenges in diverse fields, including healthcare and infection prevention. This research contributes to this domain by focusing on the synthesis, characterization, and evaluation of ZnO‐Ag nanocomposites and embedding them in PMMA matrix to obtain free‐standing flexible membrane with enhanced antibacterial potential and reusability of material. The study employs a solvothermal method for the decoration of silver nanoparticles onto zinc oxide nanorods, with the objective of harnessing the synergistic antibacterial properties of both materials. The study evaluates the antibacterial potential of the nanocomposites through well diffusion and growth kinetic assays, revealing their enhanced efficacy with a zone of inhibition (ZOI) of 21 ± 1.05 mm against Escherichia coli (E. coli). The implications of this research extend to the realm of biomedical applications, positioning the nanocomposite‐polymer membrane as promising candidates for infection prevention in healthcare premises.

Tuning the surface structure of zinc oxide nanorods by oxide entities of Ni for enhanced degradation of chlorophenoxy herbicide and chlorinated phenols

The surface of hexagonal ZnO was subjected to preliminary treatment with Ni2+ ions that transformed into a homogeneously coated layer by air calcination process in the loading range of 0.3–5 % with respect to the weight of ZnO support. The enhanced absorption in the visible region evidenced the formation of a visible light-responsive oxide entities of Ni2+ and Ni3+ that was further authenticated by multiple edges of variable energy in bandgap analysis. The photoluminescence (PL) spectra revealed the potential role of surface oxides in prolonging the life span of photon-induced excitons. The majority formation of Ni2O3 among the oxide entities, as the surface layer was substantiated by XRD and XPS analysis. The homogeneity, texture, and microstructure of the coated layer were examined by FESEM and HRTEM analysis. The charge retention ability as a function of the thickness of the coated layer was estimated by chronopotentiometry whereas the SPIES measurements coupled with Mott-Schottky analysis facilitated the fetching of the flat band potential as well as the semiconducting electrical nature of the coated materials. The loading of the catalysts as well as the impregnation level for optimum degradation/removal was evaluated in sunlight exposure for the removal of 4-chlorophenol (4-CP). The catalyst with optimum activity i.e. 0.5 % Ni2+ impregnated ZnO, was tested for the removal of potential carcinogens that included 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP) and 2,4-dichlorophenoxyacetic acid (2,4-D). The progress of the removal process was monitored by HPLC, and the extracted data was used for kinetic studies. The efficacy of the synthesized catalysts was further evaluated for the removal of a concoction of chlorophenol isomers i.e., 2-chlorophenol (2-CP), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP), both in complete spectrum and visible region (400–800 nm) natural sunlight exposure and established the kinetics of the degradation process.

Record high photocurrent density of In:Ag2S/ZnO heterojunction enabled by controllable doping for efficient solar hydrogen production

The high mobility of silver ions (Ag+) in silver sulfide (Ag2S) promotes vacancy formation, which serves as the recombination center of the photoexcited charge carriers to severely limit the photoelectrochemical activity of Ag2S. To address this issue, trivalent indium (In3+) is particularly introduced into Ag2S via low–temperature successive ionic layer adsorption and reaction (SILAR) technique, by which are the migration and the side reactions of Ag+ to form the phase impurities largely suppressed. Herein, In3+ is preferentially chosen due to its two more valence electrons with respect to that of Ag+, effectively increasing the carrier concentration of In:Ag2S to not only improve its electrical conductivity but also uplift its Fermi level. The photoexcited electron transport is thereby accelerated to more efficiently separate from the geminate holes, which is further reinforced by depositing In:Ag2S on the zinc oxide nanorods (ZnO NRs) with a relatively low–lying Fermi level. The photogenerated holes are rectified by the built–in electric field at the In:Ag2S/ZnO heterojunction to flow in an opposite direction to that of the electrons, between which the recombination is thereby suppressed. Meanwhile, the light harvesting ability of In:Ag2S/ZnO NRs is also enhanced due to its reduced band gap by In3+. Their synergistic effect renders In:Ag2S/ZnO NRs developed in the present contribution to deliver a record–high photocurrent density of 7.7 mA cm−2 under one–sun illumination, which far exceeds those of not only the undoped counterpart but also additional Ag2S–based photoelectrodes reported in the literature.

Aluminum doped zinc oxide as UV laser-based nanothermometer

Abstract This work explores thermal laser-based sensor capabilities utilising random lasing emission obtained from zinc oxide (ZnO) nanorods prepared by chemical bath deposition. The ZnO nanorods were doped with Aluminum (Al) at a concentration of 10 mM by using a simple dip method for several dip durations of 20 s, 30 s, 40 s, 60 s and 80 s, respectively. In our previous work, we successfully observed random lasing emission. Building on these findings, this work delves deeper into the thermal sensitivity of nanorod structure at room temperature within the ultraviolet (UV) range. The highest thermal sensitivity of 0.001 °C-1 was obtained from Al-doped ZnO nanorods that were dipped for 60 s. The lasing threshold was 22.92 mJ/cm2 and the lasing spectral width was 1.16 nm.

Metal-Organic Framework-Derived Ni-Doped Indium Oxide Nanorods for Parts per Billion-Level Nitrogen Dioxide Gas Sensing at High Humidity.

Detecting parts per billion (ppb)-level nitrogen dioxide in high-moisture environments at room temperature without reducing sensing performance is a well-recognized significant challenge for metal oxide-based gas sensors. In this study, metal-organic framework-derived nickel-doped indium oxide (Ni-doped In2O3) mesoporous nanorods were prepared by a solvothermal method combined with the calcination process. The sensors prepared using the obtained Ni-doped In2O3 nanorods showcase an ultrahigh response, low detection limit, and excellent selectivity. Moreover, the abundant active sites triggered by nickel doping and the capillary enhancement effect caused by mesopores endow the sensor with ppb-level (20 ppb) NO2 detection capability in high-moisture environments (95% RH) at room temperature. With the increase in humidity, the carrier concentration of the sensor increases, and the nitric acid generated by nitrogen dioxide dissolved in water can be completely ionized in water and has high conductivity. Therefore, the gas response of the sensors increases with the increase in humidity. This study establishes a promising approach for the development of trace nitrogen dioxide-sensing devices that are resilient in high-humidity environments.

The Effect of Seeding Method on The Growth of Zinc Oxide Nanorods

The paper presents the investigation of the method of seeding process for the growth of zinc oxide (ZnO) nanorods (NRs) on the glass substrate as an electron transport layer (ETL) for solar cells. The ZnO NRs were grown by using the hydrothermal method. The seeding process was done via average deposition of zinc crystallite on the glass surface, and the process was compared between with and without spin coating technique. The effect of spin coating parameters during seeding phase on the growth of ZnO nanorods was also investigated in this study. It was found that the sample prepared using the unfiltered solution without spin coating in the seeding phase exhibited the densest ZnO NRs layer with the highest absorption coefficient and high crystallinity.

Hydrothermal Growth Zinc Oxide Nanorods for pH Sensor Application

The aim of this work is to apply synthesized zinc oxide (ZnO) Nanorods using hydrothermal (HTL) growth technique for pH sensor application. The highly crystallite of ZnO Nanorods was obtained by anneal the growth ZnO Nanorods in furnace at 200 °C for 2 hours. Besides that, XRD analysis shows the produced ZnO Nanorods belonged to the (002) plane. Furthermore, Scanning Electron Microscope (SEM) images confirm that the ZnO Nanorods with hexagonal-faceted structural were successfully produced by HTL growth technique. In addition, Ultraviolet–visible (UV-Vis) spectrophotometer analysis shows that the synthesized ZnO belongs to the wide band gap semiconductor material. The growing ZnO Nanorods were then subjected to electrical measurement with various pH levels. The outcome demonstrates that the current rises as the solution changes from acidic to alkaline. Overall, our study shows a relationship between the electrical as well as the structural characteristics of ZnO Nanorods at various pH levels.

Ultra‐Low BER Encrypted Communication Based on Self‐Powered Bipolar Photoresponse Ultraviolet Photodetector

AbstractUnderwater visible light communication often faces risks such as susceptibility to external light source interference, signal distortion, and information leakage. The cuprous oxide modified gallium oxide nanorod arrays detector prepared in this study can generate bipolar photocurrents under dual‐wavelength ultraviolet light without external bias voltage. Based on it, the constructed self‐powered ultraviolet ASCII code communication system not only reduce power consumption but also significantly enhance anti‐interference capability. Furthermore, the developed solar‐blind ultraviolet AMI and HDB3 ternary code communication systems can realize non‐visible light secure communication and automatic error correction. Notably, the encrypted communication system assembled using the additive property of bipolar photocurrents can also significantly improve communication security and reliability, whose bit error rate is only 0.26‰. This achievement contributes to technical advancements in underwater channel encryption and provides valuable insights for the further application of encrypted communication coding techniques.

Low-cost fabrication methods of ZnO nanorods and their physical and photoelectrochemical properties for optoelectronic applications

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E2 (high) peak at 438 cm−1 than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications.

The Application of Ultrasound Pre-Treatment in Low-Temperature Synthesis of Zinc Oxide Nanorods

Zinc oxide, due to its unique physicochemical properties, including dual piezoelectric and semiconductive ones, demonstrates a high application potential in various fields, with a particular focus on nanotechnology. Among ZnO nanoforms, nanorods are gaining particular interest. Due to their ability to efficiently transport charge carriers and photoelectric properties, they demonstrate significant potential in energy storage and conversion, as well as photovoltaics. They can be prepared via various methods; however, most of them require large energy inputs, long reaction times, or high-cost equipment. Hence, new methods of ZnO nanorod fabrication are currently being sought out. In this paper, an ultrasound-supported synthesis of ZnO nanorods with zinc acetate as a zinc precursor has been described. The fabrication of nanorods included the treatment of the precursor solution with ultrasounds, wherein various sonication times were employed to verify the impact of the sonication process on the effectiveness of ZnO nanorod synthesis and the sizes of the obtained nanostructures. The morphology of the obtained ZnO nanorods was imaged via a scanning electron microscope (SEM) analysis, while the particle size distribution within the precursor suspensions was determined by means of dynamic light scattering (DLS). Additionally, the dynamic viscosity of precursor suspensions was also verified. It was demonstrated that ultrasounds positively affect ZnO nanorod synthesis, yielding longer nanostructures through even reactant distribution. Longer nanorods were obtained as a result of short sonication (1–3 min), wherein prolonged treatment with ultrasounds (4–5 min) resulted in obtaining shorter nanorods. Importantly, the application of ultrasounds increased particle homogeneity within the precursor suspension by disintegrating particle agglomerates. Moreover, it was demonstrated that ultrasonic treatment reduces the dynamic viscosity of precursor suspension, facilitating faster particle diffusion and promoting a more uniform growth of longer ZnO nanorods. Hence, it can be concluded that ultrasounds constitute a promising solution in obtaining homogeneous ZnO nanorods, which is in line with the principles of green chemistry.

ZnO modified carbon fiber-matrix interfacial evaluation via nanoscale digital image correlation and nanoindentation

Improving the adherence of the fiber-matrix interface is an important step for enhancing the capabilities of polymer composites. In this study, carbon fibers were modified by growing zinc oxide (ZnO) nanorods on the fiber surface using a hydrothermal approach, with the aim of increasing the interfacial area and enhancing the friction between the fiber and the matrix. To fully understand the deformation mechanisms at the interface, a microscale evaluation combining nanoindentation with digital image correlation (DIC) for mapping the deformations by using nanoscale speckles is developed in this work. The main objective of this research was to develop a protocol for speckling the modified single fiber composite and show that DIC can be used in microscopic level and to evaluate the fiber-matrix interface by means of nano indentation. The speckle pattern was created using Ti nano powder and used to generate the strain maps in the fiber-matrix interface region. A comparative analysis of DIC results from ZnO modified carbon fibers has shown that shear strains around the interfacial boundary are 60 % reduced on average, as compared to neat carbon fibers, across all nano indentations from 8mN to 65mN of peak load. Results used direct strain measurements to confirm that modification by ZnO growth on the surface of individual fibers has a significant benefit to the interfacial mechanical properties of fiber-matrix composites.

Enhancement of photoresponse for InGaAs infrared photodetectors using plasmonic WO3-x/CsyWO3-xnanocrystals.

Fast and accurate detection of light in the near-infrared (NIR) spectral range plays a crucial role in modern society, from alleviating speed and capacity bottlenecks in optical communications to enhancing the control and safety of autonomous vehicles through NIR imaging systems. Several technological platforms are currently under investigation to improve NIR photodetection, aiming to surpass the performance of established III-V semiconductor p-i-n (PIN) junction technology. These platforms include in situ-grown inorganic nanocrystals and nanowire arrays, as well as hybrid organic-inorganic materials such as graphene-perovskite heterostructures. However, challenges remain in nanocrystal and nanowire growth, large-area fabrication of high-quality 2D materials, and the fabrication of devices for practical applications. Here, we explore the potential for tailored semiconductor nanocrystals to enhance the responsivity of planar metal-semiconductor-metal (MSM) photodetectors. MSM technology offers ease of fabrication and fast response times compared to PIN detectors. We observe enhancement of the optical-to-electric conversion efficiency by up to a factor of ~2.5 through the application of plasmonically-active semiconductor nanorods and nanocrystals. We present a protocol for synthesizing and rapidly testing the performance of non-stoichiometric tungsten oxide (WO3-x) nanorods and cesium-doped tungsten oxide (CsyWO3-x) hexagonal nanoprisms prepared in colloidal suspensions and drop-cast onto photodetector surfaces. The results demonstrate the potential for a cost-effective and scalable method exploiting tailored nanocrystals to improve the performance of NIR optoelectronic devices.

A Zinc Oxide Nanorod-Based Electrochemical Aptasensor for the Detection of Tumor Markers in Saliva

Biosensors have emerged as a promising tool for the early detection of oral squamous cell carcinoma (OSCC) due to their rapid, sensitive, and specific detection of cancer biomarkers. Saliva is a non-invasive and easy-to-obtain biofluid that contains various biomarkers of OSCC, including the carcinoembryonic antigen (CEA). In this study, an electrochemical aptasensor for the detection of CEA in saliva has been developed towards the diagnosis and early screening of OSCC. This aptasensor utilized a CEA-sensitive aptamer as sensitive elements. A fluorine-doped Tin Oxide (FTO) chip with a surface modification of a zinc oxide nanorod was employed as a transducer. Electrochemical measurements were carried out to detect the responsive signals originating from the specific binding between aptamers and CEAs. The measurement results indicated that this aptasensor was responsive to different concentrations of CEA ranging from 1 ng/mL to 80 ng/mL in a linear relationship. The limit of detection (LOD) was 0.75 ng/mL. This aptasensor also showed very good specificity and regenerative capability. Stability testing over a 12-day period showed excellent performance of this aptasensor. All the results demonstrated that this aptasensor has great potential to be used for the detection of CEA in the saliva of OSCC patients. This aptasensor provides a promising method for the rapid detection of CEA with convenience, which has great potential to be used as a new method for clinical diagnoses and early screening of OSCC.