Optimum Annealing Temperature Research Articles

Study on size effect affected multi-stage micro deep drawing forming directly using pure titanium foils

In response to the problems of wrinkling and fracture in the single-stage micro deep drawing of TA1 pure titanium (Ti) foils, a blanking and multi-stage micro deep drawing (MMDD) forming system has been developed to facilitate the production of micro parts directly from sheet metal. In this study, the influence of size effect on the deformation behavior of TA1 pure Ti foils (50 μm) and the surface quality of the formed cups during MMDD was investigated. It is found that MMDD includes blank bending and the ironing effect during the continuous drawing stages. The deformation forces generated in the second and third stages exceed those resulting in the first stage, and the size effect appeared during the first stage. However, the uncertainty of the ironing effect leads to the attenuation of the size effect in the continuous stages. Moreover, {101̅0} and {112̅0} textures, are identified in the planar direction of the as-received material and contribute to wrinkling and earing, damaging the quality of parts. Subsequently, annealing at 600 °C for 60minutes results in a weakening of the {101̅0} and {112̅0} textures, with the emergence of the {0001} texture. This transformation improves the anisotropy of pure Ti and the quality of parts. But, annealing at 650 °C and 700 °C, the non-uniform plastic deformation of coarse grains adversely impacts the quality of parts, leading to wrinkling or even fracture. Consequently, the optimal annealing temperature for TA1 pure Ti foil blanks in MMDD is 600 °C.

Design and Optimization of W-Mo-V High-Speed Steel Roll Material and Its Heat-Treatment-Process Parameters Based on Numerical Simulation

W-Mo-V high-speed steel (HSS) is a high-alloy high-carbon steel with a high content of carbon, tungsten, chromium, molybdenum, and vanadium components. This type of high-speed steel has excellent red hardness, wear resistance, and corrosion resistance. In this study, the alloying element ratios were adjusted based on commercial HSS powders. The resulting chemical composition (wt.%) is C 1.9%, W 5.5%, Mo 5.0%, V 5.5%, Cr 4.5%, Si 0.7%, Mn 0.55%, Nb 0.5%, B 0.2%, N 0.06%, and the rest is Fe. This design is distinguished by the inclusion of a high content of molybdenum, vanadium, and trace boron in high-speed steel. When compared to traditional tungsten-based high-speed steel rolls, the addition of these three types of elements effectively improves the wear resistance and red hardness of high-speed steel, thereby increasing the service life of high-speed steel mill-roll covers. JMatPro (version 7.0) simulation software was used to create the composition of W-Mo-V HSS. The phase composition diagrams at various temperatures were examined, as well as the contents of distinct phases within the organization at various temperatures. The influence of austenite content on the martensitic transformation temperature at different temperatures was estimated. The heat treatment parameters for W-Mo-V HSS were optimized. By studying the phase equilibrium of W-Mo-V high-speed steel at different temperatures and drawing CCT diagrams, the starting temperature for the transformation of pearlite to austenite (Ac1 = 796.91 °C) and the ending temperature for the complete dissolution of secondary carbides into austenite (Accm = 819.49 °C) during heating was determined. The changes in carbide content and grain size of W-Mo-V high-speed steel at different tempering temperatures were calculated using JMatPro software. Combined with analysis of Ac1 and Accm temperature points, it was found that the optimal annealing temperatures were 817–827 °C, quenching temperatures were 1150–1160 °C, and tempering temperatures were 550–610 °C. The scanning electron microscopy (SEM) examination of the samples obtained with the aforementioned heat treatment parameters revealed that the martensitic substrate and vanadium carbide grains were finely and evenly scattered, consistent with the simulation results. This suggests that the simulation is a useful reference for guiding actual production.

Effects of selected physical parameters on the gamma-ray-induced EPR signal of glycine dosimeter

Electron paramagnetic resonance (EPR) dosimetric characteristics of glycine irradiated with a broad range of gamma doses, ranging from 0.1 Gy up to 100 kGy, were examined. Further physical parameters were investigated, such as irradiation temperature, dose fractionation, fading for different isothermal annealing temperatures, and UV exposure. The gamma dose response of glycine represents ~ 36% of that of alanine at a gamma dose of 5 kGy, and this ratio decreases as the gamma dose increases. The calculated detection limit is about 130 mGy. There is no significant variation in the EPR intensity of exposed glycine due to the change in the intermediate intervals between the two fractions. The optimum annealing temperature and duration time overcoming the fading impact for immediate readout of glycine after irradiation were found to be 110 °C for 15 min. UVC induces a broad peak in the unirradiated glycine sample at the same position that overlaps with the dosimetric peak of gamma rays. Keeping the glycine dosimeter in the dark is recommended to prevent the UV effect.

Evaluation of the Mechanical and Electrical Properties of Multistage Drawn Copper-Clad Aluminum Wire After Annealing Process

This study evaluates the mechanical and electrical properties of copper-clad aluminum (CCA) wire prepared with a total cross-section reduction of 89% through a multistage cold drawing process and subjected to annealing at various temperatures. In addition to the CCA wire, individual samples of oxygen-free copper and aluminum, drawn with a cross-sectional reduction of 50%, were annealed under the same temperature conditions to enable a comparative analysis. Tensile tests for strength and elongation measurements were conducted, while electrical conductivity was assessed through resistivity tests. SEM and EDS analyses were performed to examine the diffusion thickness and the composition of intermetallic compounds generated at the Al/Cu interface of CCA wire. The tensile strength of the CCA wire decreased and its elongation increased up to 250 °C, after which were maintained. As the annealing temperature increased, intermetallic compound layers of Al2Cu, AlCu, and Al4Cu9 were formed at the Al/Cu interface of the CCA wire, and their thickness increased. Electrical conductivity reaches a maximum at 200 °C and then continuously decreases, showing a negative linear correlation with an increase in the diffusion layer thickness of intermetallic compounds. The study confirmed that cold-drawn CCA wire achieves stable mechanical properties and maximum electrical conductivity at the optimal annealing temperature.

Tailoring magnetic properties of CoFeB films via tungsten buffer and capping layers

Controlling the interface between W and CoFeB-based buffer or capping layers at an appropriate temperature is essential for modifying the strength of magnetic anisotropy. In this work, we systematically explore the impact of W buffer and capping layers on the structural, topological, and magnetic anisotropy properties of W (5 nm)/CoFeB(10 nm) and CoFeB(10 nm)/W(3 nm) bilayers sputtered at room temperature (RT) and annealed at an optimal annealing temperature (TA) of 400 °C. Our findings demonstrate that the bilayer films’ uniaxial magnetic anisotropy (UMA) with out-of-plane coercivity (Hc⊥) is highly influenced by the W buffer, capping layers, and TA. Specifically, the Hc⊥ of the CoFeB layer with the buffer and capping layers annealed at 400 °C samples exceed several times the coercivity of those unannealed. CoFeB buffered with W and annealed at 400 °C shows larger Hc⊥, two-fold UMA, and higher in-plane UMA energy density (Keff) than the CoFeB/W bilayers, which can be attributed to the W buffer layer inducing the crystallization of CoFeB during annealing. The W buffer, capping layers, and the TA for W and CoFeB-based bilayer samples significantly alter the surface morphology, grain sizes, and surface roughness. The XRD analysis reveals nano-crystallites embedded in the larger grains of the 400 °C annealed samples. Hence, this work offers a promising approach to achieving high thermal stability of UMA in W and CoFeB-based spintronic applications.

Preparation and characterization of temperature-induced ultrasensitive SERS large-scale vertical Au nanosphere dimers

Plasmonic dimers have a very wide range of applications as a unique platform for studying the fundamental effects of plasmonics. Most dimer structures are prepared by chemical methods and direct-writing methods, such as coupling agents and lithography. These methods are often complex and expensive. Here, we prepared Au nanospheres (AuNSs) by layer-by-layer (LBL) deposition, used polymethyl methacrylate (PMMA) as a spacer layer, and then annealed the deposited AuNSs to orient the assembly and integrate them together. In this paper, suitable PMMA spin coating conditions and optimal annealing temperatures were explored, and large-scale AuNSs-PMMA-AuNSs(NSs-P-NSs) composed of vertical Au nanosphere dimers were prepared successfully. The detection limits of this substrate can reach 4 × 10−12 M/L and 4 × 10−10 M/L for Rhodamine 6 G (R6G) and Crystal Violet (CV), respectively, demonstrating excellent Raman activity. In addition, the sensitivity of detecting aspartame (APM) is 0.015625 g/L. This method is not only simple to operate but also allows the preparation of a large-scale uniform substrate with excellent detection capabilities.

A sensitive batch detection of banana bunchy top virus using SYBR® Green real-time PCR.

Banana bunchy top virus (BBTV) is the most destructive viral disease of banana crop in the Philippines. The disease causes heavy damage to important local varieties, 'Lakatan' and 'Cavendish'. Infected planting materials can cause long-term disease transmission causing geographical location to dictate genetic variation among viral strains. Hence, there is a need for an efficient and reliable quarantine detection procedure. This study developed a high-throughput real-time PCR protocol for batch detection of BBTV. A primer set derived from the DNA-R region of the virus was designed for specific BBTV detection. Tests for optimal annealing temperature, sample load, and sensitivity were performed. Finally, the cost per sample was compared to conventional end-point PCR. Optimization of the annealing temperature, from 55.5 ℃ to 63.5 ℃, yielded virus detection. The detection protocol developed was efficient to detect BBTV from a leaf disc measuring up to 5mm diameter and weight of approximately 3mg. DNA from infected leaf discs was detectable up to 1:10000 dilution. Sample pooling was detectable up to 1:99 infected to healthy leaf disc ratio. This sensitive and cost-efficient batch detection method for BBTV detection will be useful for quarantine services and various diagnostic applications.

Wheatstone Bridge MEMS Hydrogen Sensor with ppb-Level Detection Limit Based on the Palladium-Gold Alloy.

On some occasions, such as new energy clinics, monitoring the trace hydrogen at the ppb level is necessary. The traditional resistive hydrogen sensors based on the Pd alloys are very difficult to realize such an extremely low detection limit. To achieve a detection limit at the ppb level and also ensure good stability, a MEMS hydrogen sensor was designed in a suspended Wheatstone bridge structure, with all four resistive arms defined on a sputtered Pd-Au alloy thin film. For the Wheatstone bridge sensor, absolute response (Ra) and relative response (Rs) are defined to describe the sensitivity of the sensor, and the effect of annealing temperature on baseline drift is investigated using the baseline zero drift parameter (DBZD). By testing the sensors across a hydrogen concentration range of 20 ppb to 3 v/v%, the optimal annealing temperature (250 °C) and operating temperature (60 °C) were identified. Under these conditions, the sensor exhibited a detection limit as low as 20 ppb with a power consumption of only 4.6 mW. At the same time, the response and recovery times of the sensor were 6 and 19 s, respectively, toward 3 v/v% hydrogen. After testing over a 100-day period, Ra fluctuated only 0.0026%, indicating that the hydrogen sensor had good long-term stability for low-concentration detection. More results also showed that the sensor has good repeatability, selectivity, and humidity resistance. With the wide measurement range (20 ppb to 3 v/v%), the sensor has the potential to meet hydrogen detection requirements in multiple scenarios.

Influence of annealing temperature on Fe₂O₃ nanoparticles: Synthesis optimization and structural, optical, morphological, and magnetic properties characterization for advanced technological applications

In this study, Iron oxide nanoparticles (Fe₂O₃ NPs) were synthesized using iron chloride hexahydrate (FeCl3·6H2O) and ammonia solution through a straightforward co-precipitation method. The nanoparticles were annealed at temperatures of 100 °C, 300 °C, 500 °C, 700 °C, and 900 °C, with one sample left unannealed. Comprehensive analyses were performed using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Zeta potential, Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and UV–Vis Spectrophotometry. The XRD patterns confirmed the presence of both Maghemite (γ-Fe2O3) and Hematite (α-Fe2O3) phases, with a phase transition observed between 100 °C and 300 °C, and the most pronounced transition occurring at 500 °C. At this optimal temperature, the crystallite size was 19.14 nm, the average particle size was 37.36 nm, and the band gap energy was measured at 1.76 eV. SEM images revealed that nanoparticles formed clusters as the annealing temperature increased. The zeta potential measurements showed a range from 6.12 mV at 100 °C to −1.9 mV at 900 °C, indicating changes in particle stability. DLS analysis indicated a size increase from 86.81 nm at 300 °C to 1577 nm at 900 °C, reflecting aggregation trends. The reduction in band gap energy with higher temperatures is attributed to enhanced crystallinity and increased particle size. The magnetic properties of Fe₂O₃ NPs were evaluated using a Physical Property Measurement System (PPMS), revealing an increase in magnetic response with rising annealing temperatures. The transition from superparamagnetic γ-Fe₂O₃ to weakly ferromagnetic α-Fe₂O₃ was confirmed through changes in the hysteresis loop area and shape. These findings suggest that 500 °C is the optimal annealing temperature for producing Fe₂O₃ NPs with desirable properties for applications in targeted drug delivery, MRI contrast enhancement, and environmental remediation. This research advances the engineering of Fe₂O₃ NPs, paving the way for their use in various technological applications.

Photoelectrochemical and Structural Insights of Electrodeposited CeO2 Photoanodes

Cerium dioxide (CeO2) is a promising material for photoelectrochemical applications, requiring a thorough understanding of the interplay between its properties and structure for optimal performance. This study investigated the photoelectrochemical performance of CeO2 photoanodes immobilized by electrodeposition on glass substrates, focusing on the correlation between the annealing temperature and structural, optical, and electrical changes. CeO2 coatings were obtained via chronoamperometry in an aqueous solution of 25 mM CeCl3 and 50 mM NaNO₃. The photoelectrochemical characterization included the evaluation of photoactivity, current density, stability, and recombination using linear sweep voltammetry (LSV) and chronoamperometry (CA). Charge transfer resistance, flat-band potential, and capacitance were assessed through impedance spectroscopy. The optimal annealing temperature for this material was found to be 600 °C as it resulted in the lowest charge transfer resistance and increased photocurrent, which was attributed to enhanced crystallinity and variations in the Ce3+/Ce4+ ratio.

Effect of annealing on ion-beam-sputtered hafnium oxide thin films properties

HfO2 films are high laser damage-threshold and low-absorption thin-films that can be utilized for a broad range of optoelectronic and optical applications. In this study, HfO2 thin films were prepared via dual ion beam sputtering followed by annealing in the atmosphere at temperatures ranging from 200 to 700 °C. The optical properties, microstructure, film stress, and absorption loss of the HfO2 films at various annealing temperatures were then systematically characterized. The results revealed that the properties of the films were improved after annealing at temperatures below 500 °C. Specifically, at an optimal annealing temperature of 400 °C, the residual stress of the films was minimized close to zero and the absorption loss was as low as 1 ppm. However, at annealing temperatures reaching 600 °C, the films began to crystallize, leading to the deterioration of their optical properties. Optimizing the process parameters for HfO2 thin film deposition is crucial for developing the next generation of high-performance laser optics.

Enhanced Pyroelectricity Over Extended Thermal Range in Flexible Polymer Thin Films

AbstractPolymer‐based pyroelectric thin films are crucial functional materials at the core of flexible and lightweight electronic devices, such as wearable monitoring sensors, energy harvesters, and infrared detectors. Nevertheless, the pyroelectric properties of the polymer films, such as poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE)), vanish when the surrounding temperature exceeds the ferroelectric‐to‐paraelectric transition temperature, and thus limits their pyroelectric performance to a low‐temperature range. Herein, to mitigate this issue by employing a new class of P(VDF‐TrFE) copolymer which has a low TrFE molar content is proposed. Fine‐tuning of the structure through thermal annealing in a vacuum environment significantly favors robust and highly polarized polymer films with a large area. Electric poling combined with an optimal annealing temperature (110–120 °C) gives highly ordered ferroelectric crystalline domains in the polymer films. Consequently, this remarkably broadens the temperature range (roughly up to 140 °C) for which the polymer film still presents high pyroelectric properties (pyroelectric coefficient 50 µC (m2K)−1). This study provides an alternative choice for pyroelectric polymer films with enhanced pyroelectricity in applications that require wider temperature ranges.

Tunable annealing effect to enhance structural and magnetic properties of spinel cobalt magnesium ferrite nanoparticles

Cobalt magnesium ferrite nanoparticles, with the chemical formula Co0.5Mg0.5Fe2O4 (CMFO), were synthesized via co-precipitation and subjected to annealing at 200–800 °C with a step size of 200. Thermal analysis for the as-dried sample was investigated through thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The presence of a plateau region in the DTA curve above 366 °C, combined with the slight weight loss noted in the TGA curve, indicates that the ferrite sample, specifically CMFO, has successfully transitioned into its final phase. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) analysis unveiled the formation of spinel CMFO NPs belonging to the Fd-3m space group. The Williamson–Hall method showed particle size increasing from 8.20 to 52.15 nm and tensile microstrain decreasing from 6.90 to 1.84 × 10−3 with higher annealing temperatures, noted by the shift of the (311) plane. TEM images confirmed the formation of smaller nanoparticles with minimal agglomeration. Particles of nearly uniform size are achieved at the optimum annealing temperature of 600 °C, owing to its narrow distribution profile. The experimental magnetization data were analyzed using the Langevin function and the law of approach to saturation to determine the saturation magnetization, spanning from 15.46 to 43.90 emu/g. The magnetic characteristics of the annealed samples exhibited a rise in coercive force, reaching up to 349.74 Oe with the elevation of the annealing temperature. The range of attributes exhibited by CMFO makes it highly advantageous for various applications, including sensor technology, high-frequency devices, and energy storage devices.

A molecular genetic toolkit for the differential expression analysis of soybean β-conglycinin subunit genes

The majority of proteins in soybean seeds are storage ones, including β-conglycinin and glycinin, which are necessary for seed germination. At the same time, they are the most valuable soy proteins used in the food industry, since their subunit composition and proportion of total protein can affect the quality of the resulting food product. β-conglycinins are trimers with different composition of subunits which are designated as α', α, β and encoded by the CG-1, CG-3, and CG-4 genes, respectively. The PCR analysis employed a model soybean cultivar ‘Sentyabrinka’. A complementary DNA synthesized from the RNA isolated from seeds of the studied cultivar served as a template. The in silico created pairs of primers for CG-1, CG-3, and CG-4 gene transcripts were used. As the result of PCR and the analysis of the obtained electrophoregrams, optimal annealing temperatures of primers for the CG-1, CG-3 and CG-4 genes were selected, at which only the characteristic fragment was observed. Thus, a molecular genetic toolkit has been developed for a comprehensive study of the qualitative and quantitative composition of soybean protein and can be used for further analysis of differential expression of genes responsible for the synthesis of β-conglycinin subunits.

A droplet digital PCR method for the detection of scale drop disease virus in yellowfin seabream (Acanthopagrus latus).

In this study, a ddPCR method for the detection of scale drop disease virus (SDDV) in yellowfin seabream (Acanthopagrus latus) was established based on Real-time fluorescence quantitative PCR detection methods and principles. The reaction conditions were optimized, and the sensitivity, specificity, accuracy, and reproducibility were assessed. The results showed that threshold line position was determined to be 1900 by the ddPCR method; the optimum annealing temperature for SDDV detection by the ddPCR method was 60°C; the limit of detection was 1.4-1.7 copies/μL; the results of specific detection of other common viruses, except for SDDV specific amplification, were all negative; and the relative standard deviation (RSD) for the reproducibility validation was 0.77%. The samples of yellowfin seabream (Acanthopagrus latus) liver, spleen, kidney, heart, intestine, brain, blood, muscle, skin and ascites with three replicates, respectively, were tested using the ddPCR method, and the results were consistent with clinical findings. The ddPCR method established in this study has the advantages of high sensitivity, high specificity, good reproducibility and simple steps for the quantitative detection of SDDV, which could be used for the nucleic acid detection of clinical SDDV samples, and provided a new quantitative method for the diagnosis of yellowfin seabream SDDV in the early stage of pathogenesis.

Study on the effect of annealing temperature on the optical characteristics and microstructure of Sb2Se3 thin films

To achieve high conversion efficiency in Sb2Se3 thin films, the effects of different annealing temperatures on the optical properties and microstructure were investigated. The experiment shows that annealing improves Sb2Se3 films' refractive index, absorptivity, and reduces the optical band gap. The first-principle theoretical analysis reveals that defects in the films such as SbSe2, SbSe3, VSe2, and VSe3 significantly affect their optical band gap. Based on the XRD (X-ray diffraction) patterns, the half-height widths, average grain sizes, microstrains and dislocation densities of the diffraction peaks have been calculated. The results show that the optimal annealing temperature is 325 °C. Finally, EDS (Energy Dispersive Spectrometer) and Raman spectroscopy were used to explain the reasons for the changes in the optical properties and internal structure of the film with the annealing temperature from the perspectives of the changes in the film components and the bonding properties between the atoms.

Development of a Multiplex RT-PCR for Simultaneous Detection of Five Actinidia Viruses

Kiwifruit (Actinidia spp.) is a perennial fruit tree, and the fruit of kiwifruit is economically and nutritionally important worldwide. To date, approximately 23 species of kiwifruit viruses have been reported worldwide. As for the detection method for kiwifruit viruses, previous reports mostly used the single RT-PCR detection method. In the detection of kiwifruit viruses, multiplex RT-PCR has the advantages of being fast, reliable and inexpensive. In this study, a stable, efficient and reliable multiplex RT-PCR method for the detection of the five most common kiwifruit viruses was established. The concentrations of Mg2+ and HS-Taq and the annealing temperature in the multiplex PCR system were optimized. The results indicate that the optimal annealing temperature was 56 °C; the optimal concentration of added Mg2+ was 2 mM; and the optimal concentration of HS-Taq was 1.0 U/μL. The stability of the optimized multiplex RT-PCR system was verified by field sample testing, and the results showed that the multiplex RT-PCR system was stable, efficient and reliable. This will provide much convenience for the detection of kiwifruit viruses in the future.

Critical factors for enhancing electrical performance in LaGdO3 capacitor

This study investigates the characteristics of metal/LaGdO3/Si capacitors using LaGdO3 as the dielectric material. LaGdO3 thin films were deposited using radio-frequency magnetron sputtering, and the effects of different process parameters, such as annealing temperature, electrode materials, and oxygen ratio, on the capacitance characteristics were investigated. Results showed that the presence of oxygen vacancies affects the dielectric constant, flat-band voltage, and breakdown field of LaGdO3 films. The optimal annealing temperature for the LaGdO3/Si stack was identified to be 600 °C, resulting in a dielectric constant of 13.9 and a flat-band voltage shift of 0.1 V. Introducing 10 % O2 during deposition effectively repaired oxygen vacancies in the film, while excessively high oxygen proportions resulted in a lower dielectric constant and a higher flat-band voltage shift. Moreover, the electrode material was found to affect the capacitance characteristics. The dielectric constants for Al/LaGdO3/Si, Ti/LaGdO3/Si, and Pt/Ti/LaGdO3/Si capacitors were 10.0, 16.3, and 17.3, respectively. The flat-band voltage shifts were −0.7, −0.42, and −0.03 V, with hysteresis voltages of 345, 117, and 32 mV, respectively. The Pt/Ti/LaGdO3/Si device exhibited the lowest oxide defect density, indicating superior interface quality and potentially enhanced device performance. In addition, the band diagrams for metal/LaGdO3/Si were constructed. This study demonstrates that oxygen vacancies and electrode materials are crucial factors influencing the capacitance characteristics of LaGdO3 films. The electrical properties of LaGdO3 films can be effectively improved by controlling process parameters, enhancing their potential for applications in capacitors and other electronic devices.

Synthesis of MgB2 films on Hastelloy-C276 tape with Al2O3/Y2O3/MgO/LaMnO3 buffer layers by magnetron sputtering in co-evaporation mode

This study presents the initial results of developing a technology for synthesizing a flexible superconducting magnesium diboride composite on a Hastelloy®-C276TM substrate coated with Al2O3/Y2O3/MgO/LaMnO3 buffer layers. The superconducting composite was deposited by magnetron sputtering from two Mg and B targets, followed by vacuum annealing at various substrate temperatures ranging from 400 °C to 700 °C. The superconducting transition temperature T c ≈ 22 K, with a transition width ΔT ≈ 1 K, and critical current J c ≈ 500 kA cm−2 (T= 5 K, H = 2 T) and J c ≈ 11 kA cm−2 (T = 15 K, H = 2 T) at the optimal annealing temperature of 400 °C.

A simple PCR-based quick detection of the economically important oriental fruit fly, Bactrocera dorsalis (Hendel) from India.

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a significant economic and quarantine pest due to its polyphagous nature. The accurate identification of B. dorsalis is challenging at the egg, maggot, and pupal stages, due to lack of distinct morphological characters and its similarity to other fruit flies. Adult identification requires specialized taxonomist. Existing identification methods are laborious, time consuming, and expensive. Rapid and precise identification is crucial for timely management. By analyzing the variations in the mitochondrial cytochrome oxidase-1 gene sequence (Insect barcoding gene), we developed a species-specific primer (SSP), DorFP1/DorRP1, for accurate identification of B. dorsalis. The optimal annealing temperature for the SSP was determined to be 66°C, with no cross-amplification or primer-dimer formation observed. The SSP was validated with B. dorsalis specimens from various locations in northern and eastern India and tested for cross-specificity with six other economically significant fruit fly species in India. The primer specificity was further confirmed by the analysis of critical threshold (Ct) value from a qPCR assay. Sensitivity analysis showed the primer could detect template DNA concentrations as low as 1 pg/µl, though sensitivity decreased at lower concentrations. Sequencing of the SSP-amplified product revealed over >99% similarity with existing B. dorsalis sequences in the NCBI GenBank. The developed SSP reliably identifies B. dorsalis across all developmental stages and sexes. This assay is expected to significantly impact pest identification, phytosanitary measures, and eradication programs for B. dorsalis.