Fluorescence Detection System Research Articles

A CRISPR/Cas12a-assisted on-fibre immunosensor for ultrasensitive small protein detection in complex biological samples

Tracking trace amounts of analytes directly from low volumes of complex biological samples remains an ongoing challenge in precision diagnostics, as the commonly used immunosorbent assays have limited sensitivity. Herein, a CRISPR/Cas12a assisted on-fibre immunosensor (CAFI) was developed based on an antibody-analyte-aptamer sandwich structure, in which a single strand DNA aptamer was applied to detect the analyte while triggering the CRISPR/Cas12a fluorescent detection system to amplify the analyte signal. This novel CAFI biosensing system was fabricated on a glass fibre surface with an antifouling PEG polymer brush modified for the detection of a spectrum of small molecules from complex media. In comparison with a conventional ELISA system, CAFI has a 1,000-fold higher sensitivity with the limit of detection for IFN-γ down to 1 fg mL−1 (58.8 aM). It also has a tuneable linear detection range that can be easily adjusted within the range 1 fg mL−1 to 100 pg mL−1 (5 orders of magnitude), meeting the requirements of the demanding diagnostic scenarios. CAFI has successfully been demonstrated by detecting IFN-γ from a diverse complex biological sample type, including human serum, whole blood, perspiration, and saliva. Moreover, CAFI is applicable for the detection of other analytes by simply modifying the capture antibody and detection aptamer, demonstrated here with insulin. All these superior capabilities of CAFI make it a suitable technology to measure proteins in low (100 μL) volume complex biological samples.

Simultaneous detection of melatonin and six metabolites of L-tryptophan pathway in rat gastric mucosa.

Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine synthesized in vertebrates mainly in the pineal gland, and is known to be involved mainly in thermoregulation and control of the circadian rhythm. That indoleamine can affect the auto-, para- and endocrine pathways, regulating body functions and affecting the metabolism of animals and humans. In addition to the pineal gland, melatonin can be synthesized in many extra-pineal tissues, mainly in the gastrointestinal tract. Previous studies have shown that melatonin plays an important role in the defense system of the gastrointestinal mucosa, demonstrating a protective effect on the gastrointestinal tract and the acceleration of healing of chronic ulcers through the scavenging of reactive oxygen metabolites (ROS) and the activation of protective nitric oxide (NO) and vasodilator neuropeptides released from the sensory afferent neurons. The process of converting the melatonin precursor L-tryptophan into melatonin is already known, but not all aspects of this process for the synthesis of other metabolites of this pathway have been fully elucidated and this issue remains poorly understood. In this study, the conversion of L-tryptophan to melatonin and other metabolites was determined in gastric mucosa collected from rats with or without intragastric (i.g.) melatonin or L-tryptophan administration, both administered at a single dose of 50 mg/kg. For the determination of five metabolites of L-tryptophan: kynurenine, 5-hydroxytryptamine, 5-hydroxytryptophan, anthranilic acid, indole-3-acetic acid together with melatonin, we have modified the previously developed high-performance liquid chromatography (HPLC) method using a native fluorescence detection system and UV-VIS. The obtained results show that: 1) L-tryptophan is converted into melatonin in the gastric mucosa during the day, e.g. after eating a meal containing L-tryptophan, as it was imitated and confirmed by our study, in which this amino acid was administered directly to the stomach, 2) the gastric mucosa is capable of producing melatonin in much greater amounts than those recorded in the blood serum of rats given a single dose of L-tryptophan, and 3) apart from melatonin, the only serum levels of these five metabolites of the L-tryptophan metabolic pathway are detectable, while their level in the gastric mucosa is low and barely detectable under physiological conditions. Our present observations support the notion that the gastric mucosa is one of the main sources of melatonin production from L-tryptophan outside the pineal gland.

Microparticle-tagged image-based cell counting (ImmunoSpin) for CD4\u2009+\u2009T cells

Affordable point-of-care (POC) CD4 + T lymphocyte counting techniques have been developed as alternatives to flow cytometry-based instruments caring for patients with human immunodeficiency virus (HIV)-1. However, POC CD4 enumeration technologies can be inaccurate. Here, we developed a microparticle-based visual detector of CD4 + T lymphocytes (ImmunoSpin) using microparticles conjugated with anti-CD4 antibodies, independent of microfluidic or fluorescence detection systems. Visual enumeration of CD4 + T cells under conventional light microscope was accurate compared to flow cytometry. Microparticle-tagged CD4 + T cells were well-recognized under a light microscope. ImmunoSpin showed very good precision (coefficients of variation of ImmunoSpin were ≤ 10%) and high correlation with clinical-grade flow cytometry for the enumeration of CD4 + T cells (y = 0.4232 + 0.9485 × for the %CD4 + T cell count, R2 = 0.99). At thresholds of 200 and 350 cells/µL, there was no misclassification of the ImmunoSpin system compared to the reference flow cytometry. ImmunoSpin showed clear differential classification of CD4 + T lymphocytes from granulocytes and monocytes. Because non-fluorescence microparticle-tags and cytospin slides are used in ImmunoSpin, they can be applied to an automatic digital image analyzer. Slide preparation allows long-term storage, no analysis time limitations, and image transfer in remote areas.Graphical abstract

LIFGO: A modular laser-induced fluorescence detection system based on plug-in blocks

In this work, a laser-induced fluorescence (LIF) detection system built in a modular assembling mode was developed based on commercial LEGO blocks and 3D printed blocks. We designed and fabricated a variety of 3D printed building blocks fixed with optical components, including laser light source, filters, lens, dichroic mirror, photodiode detector, and control circuits. Utilizing the relatively high positioning precision of the plug-in blocks, a modular construction strategy was adopted using the flexible plug-in combination of the blocks to build a highly sensitive laser-induced fluorescence detection system, LIFGO. The LIFGO system has a simple structure which could be constructed by inexperienced users within 3 h. We optimized the structure and tested the performance of the LIFGO system, and its detection limits for sodium fluorescein solution in 100 μm i.d. and 250 μm i.d. capillaries were 7 nM and 0.9 nM, respectively. Based on the LIFGO system, we also built a simple capillary electrophoresis (CE) system and applied it to the analysis of DNA fragments to demonstrate its application possibility in biochemical analysis. The separation of 7 fragments in DL500 DNA markers were completed in 600 s. Because of the features of low cost (less than $100) and easy-to-build construction, we introduced the LIFGO system to the experimental teaching of instrumental analysis for undergraduate students. The modular construction form of the LIF detection system greatly reduces the threshold of instrument construction, which is conducive to the popularization of the LIF detection technique in routine laboratories as well as the reform of experimental teaching mode.

Rapid and facile electrospray preparation of CsPbBr3@PMMA fluorescent microspheres for fluorescent detection of ALP in biological samples

All-inorganic cesium lead halide perovskite quantum dots (QDs) have attracted more attention due to their excellent optoelectronic and photovoltaic properties. However, there are few applications in biochemical detection based on their unique photoluminescence property mainly because of the instability to external stimulus. In this work, we focus on a rapid preparation method of CsPbBr3@poly (methyl methacrylate) (PMMA) fluorescent composite microspheres based on electrospray to protect CsPbBr3 QDs from the external stimuli and stabilize them in aqueous environment. The CsPbBr3@PMMA composite microspheres effectively retained over 70% fluorescence intensity after being immersed in deionized water for 20 days. Based on the effective quenching of CsPbBr3@PMMA composite microspheres by MnO2 nanosheets, we developed a simple, label-free, low-cost, and facile fluorescent detection system for assay of alkaline phosphatase (ALP) in biological samples. The method shows a good linear relationship from 10.0 mU/mL to 100 mU/mL (R2 = 0.998) with the detection limit of 4.85 mU/mL and the recovery range of 95.1–110%. In summary, the PMMA coating can simply and effectively stabilize the CsPbBr3 QDs and preserve the luminescence of the CsPbBr3 QDs. The excellent applicability of the composite microspheres-based fluorescent detection system in human serum samples further demonstrates the potential application in the aqueous phase-based biochemical detection for clinical diagnosis and biomedical research.

Take a good catch at the scat: carboxylic and sulfonic acid profiles as a non-invasive tool for species identification and sex determination in neotropical carnivores

ABSTRACT There is an increasing interest in the use of noninvasive monitoring methods, such as the use of chemical profiles obtained from noninvasive samples. Here, we propose the use of carboxylic and sulfonic acids profiles obtained from scats as a noninvasive tool to identify mammalian carnivoran species and for sex determination. We used High-Performance Liquid Chromatography (HPLC) coupled to a Laser-Induced Fluorescence (LIF) detection system (HPLC-LIF) to retrieve carboxylic and sulfonic acids profiles from scats of five mammalian carnivores: Puma concolor, Herpailurus yagouaroundi, Leopardus pardalis and Felis catus (all Felidae) and Nasua nasua (Procyonidae). We were able to unambiguously identify the species and determinate the sex for all fecal samples through the pattern of presence-absence of carboxylic and sulfonic acids (digital coding). The method allowed the discrimination of the evaluated species of the Carnivora, even between closely related and ecologically similar felids. Moreover, our method is low cost and can be executed in a short period of time. Further investigation is necessary to evaluate if the method’s discriminatory power is applicable to other mammalian species. Additionally, the method’s potential to ascertain other intraspecific traits such as age, identity, reproductive and health status is yet to be determined.

Cost-Effective Multiplex Fluorescence Detection System for PCR Chip.

The lack of portability and high cost of multiplex real-time PCR systems limits the device to be used in POC. To overcome this issue, this paper proposes a compact and cost-effective fluorescence detection system that can be integrated to a multiplex real-time PCR equipment. An open platform camera with embedded lens was used instead of photodiodes or an industrial camera. A compact filter wheel using a sliding tape is integrated, and the excitation LEDs are fixed at a 45° angle near the PCR chip, eliminating the need of additional filter wheels. The results show precise positioning of the filter wheel with an error less than 20 μm. Fluorescence detection results using a reference dye and standard DNA amplification showed comparable performance to that of the photodiode system.

Ratiometric fluorescent detection system based on dual-driving catalysis of CuO nanozyme with a classical univariate calibration for the determination of ascorbic acid in serum and fruits

Copper oxide nanoparticles (CuO NPs) as nanozymes have received extensive attention due to their numerous advantages such as water solubility and biomimetic effects. In this work, we combined the inherent oxidase and ascorbate oxidase mimetic activity of CuO NPs to construct a ratiometric fluorescence system for the detection of ascorbic acid (Vitamin C, AA) in serum and fruits. By feat of the dual mimic nanozymatic activity of CuO NPs, the sole substrate o-phenylenediamine (OPD) can be catalyzed to attain yellow fluorescent 2,3-diaminophenazine (oxOPD), while oxidized AA will react with the pristine OPD to form blue fluorescent product. This method has a sensitive response to AA with a good linear relationship in the concentration range of 1–150 μM and low detection limit of 0.16 μM. Practical sample detection of AA in human serum and fruits can be realized reasonably with the recovery rates between 84.83% and 87.28% and 88.53%-113.1%, respectively. More conveniently, the method can be successfully used for scanning measurement analysis through the associated application (ColorAssist) on smartphones and portable UV lamps.

Determination of the SLAMF1 self-association affinity constant with sedimentation velocity ultracentrifugation

Signaling lymphocytic activating molecule family member 1 (SLAMF1 or CD150) is a cell surface glycoprotein expressed on various immune populations, regulating cell-cell interactions, activation, differentiation, and inflammatory responses and has been suggested as a potential target for inflammatory diseases. Signaling is believed to be mediated by high-affinity homophilic interactions; the recombinant soluble form of SLAMF1 has optimal activity in the range of 20 μg/mL. This contradicts with a rather weak homo-dimerization binding constant (KD) value reported previously; however, the analytical approach and data analysis suffered from various technical limitations at the time and therefore warrants re-examination. To address this apparent discrepancy, we determined the KD of soluble SLAMF1 using sedimentation velocity analytical ultracentrifuge (SV-AUC). A globally fitted monomer-dimer model properly explains the data from a wide concentration range obtained with both UV and fluorescence detection systems. The analysis suggests the dimerization KD value for human SLAMF1 is 0.48 μM. Additionally, our data show that SLAMF1 self-association is not driven by non-specific binding to glycans supporting the view of specific protein-protein interaction. We anticipate antibody biotherapeutics capable of modulating the biological consequences of SLAMF1 interactions will be readily identified.

Delineation of the healthy rabbit liver by immunohistochemistry – A technical note

Liver diseases pose a big global health problem and liver failure may result from viral infection, overnutrition or tumors. Studying pathologic liver tissue demands for accurate and specific histological stainings and immunohistochemical labellings, including chromogenic and fluorescent approaches. Moreover, a reliable set of healthy liver stainings and labellings are required, to provide a baseline or reference for the pathological situation.Here, we used the liver tissue of a healthy rabbit and compared different histological key steps, such as paraffin embedding after formalin fixation versus cryopreservation; or an antigen retrieval (AR) step in processing paraffin sections versus the same procedure without AR; or chromogenic with fluorescent detection system, respectively. Moreover, we provide images of serial sections, where we stained the same morphological structure with different markers, including collagen I, collagen III, fibronectin, α-SMA, elastin, protease-activated receptor-2 (PAR-2) which is an inflammation-related marker, ki67 for proliferating cells, and orcein (as negative control for pathological aberrations like Wilson disease). Differences between conditions were quantitatively assessed by measuring the colour intensity.Generally, we observed that cryosections exhibited a stronger signal intensity in immunohistochemically labelled sections than in paraffin sections; however, the strong staining got slurred, which sometimes hampered proper identification of morphological structures at higher magnifications. Moreover, there was a clear increase in signal intensity for paraffin sections when an AR step was performed compared to condition without AR. Results for mouse isotype staining as a negative control clearly supported those findings.Different stainings of the portal triad, the central vein and the bile ducts revealed a clear-cut distribution of extracellular matrix components, with prominent fibronectin and elastin around the lumen of the central vein as well as a patchy PAR-2 expression. As for the bile ducts, complete absence of α-SMA and PAR-2 was found at the margins, however, collagen I expression and elastin were positive and showed a strong signal. Like this, we provide useful and valuable reference images for researchers using the rabbit liver model. It may help to decide which of the immunohistochemical protocols are valuable to reach a certain aim and which protocols lead to the best visualization of the target structure.

Telechemistry 2.0: Remote monitoring of fluorescent chemical reactions

Implementation of the Internet-of-Things in chemistry research has the potential to improve research methodologies. Here, we describe a cloud-integrated real-time laboratory monitoring system for: (i)monitoring reactions involving fluorescent chemical species, and (ii) monitoring laboratory environment for safety purpose. A probe-type fluorescence detection system has been constructed to monitor reactions that involve fluorescent molecules. This device incorporates an in-house-built 3D-printed probe, two optical fibers, a light-emitting diode, a photoresistor, and a microcontroller board (MCB). The MCB relays experimental data to a single-board computer (SBC), which then uploads the data to a cloud-based platform (ThingSpeak) for data storage and visualization. The SBC is also connected to auxiliary sensors to measure relative alcohol vapor concentration, temperature, and humidity at different locations in the laboratory. The device has been validated and tested for its performance by monitoring a fluorescent chemical reaction (synthesis of fluorescent gold nanoclusters) for a period of 12 h.

A quantum dot microspheres-based highly specific and sensitive three-dimensional microarray for multiplexed detection of inflammatory factors

The development trend of in vitro diagnostics is to obtain various biological information from a sample at extremely low concentration and volume, which has promoted its progress in accurate and sensitive multiplexed detection. Here, we developed a single color quantum dot (QD) based three-dimensional (3D) structure matrix microarray and conducted the detection of two inflammatory factors (C-reactive protein (CRP) and serum amyloid A (SAA)) by a self-built fluorescence detection system. This strategy increased detection sensitivity by immobilizing the antibody specifically on the 3D substrate because it captured more than about 7 times of ‘effective’ antibodies compared to the two-dimensional (2D) plane. Compared to the dual QDs-2D fluorescence-linked immunosorbent assay, the limit of detection (LOD) of 3D microarray based on QDs modified with amphiphilic polymers has been further improved to 0.11 ng ml−1 for SAA assay and to 0.16 ng ml−1 for CRP assay, respectively. By using QD microspheres (SiO2@QDs@SiO2-COOH, containing approximately 200–300 hydrophobic QDs on per SiO2 sphere) as fluorescent labels, the LOD for CRP and SAA of 3D microarray reached as high as 15 pg ml−1 and 86 pg ml−1, and the sensitivity was further improved by 28-fold and 425-fold, respectively. Because of its excellent performance, this QD microspheres-based 3D microarray has great application potential for highly sensitive and multiplexed quantitative detection of other biomarkers, small molecules, and antibiotic residues in biomedicine and food safety.

Development of carbon dot-thiochrome-based sensing system for ratiometric fluorescence detection of D-penicillamine.

A simple and rapid ratiometric fluorescent sensing system for D-penicillamine (D-PA) determination is developed based on yellow carbon dots (Y-CDs) combined with thiochrome (oxVB1) for the first time. The oxidization of thiamine (VB1) can be catalyzed by Alkaline-hydrolyzed artemisinin (a-ART) to form oxVB1, which leads to the occurrence of fluorescence emission peak at 466nm. Furthermore, the oxidation reaction between a-ART and VB1 could be inhibited by D-PA, and accompanied with the decrease of fluorescence at 466nm. However, the fluorescence peak of Y-CDs as an internal reference at 566nm was almost unchanged. The ratiometric signal changes contributed to a robust and sensitive D-PA sensing. Under the optimal condition, a good linear response for the D-PA detection was obtained in the ranges of 0.5-50μM with a detection limit of 0.33μM. In addition, Y-CDs and thiochrome-based sensing system was applied to D-PA determination in real samples and obtained acceptable results. We developed a new carbon dots/thiochrome fluorescent nanoprobe for ratiometric fluorescence sensing of D-penicillamine.

CRISPR/Cas12a-Based Ultrasensitive and Rapid Detection of JAK2 V617F Somatic Mutation in Myeloproliferative Neoplasms.

The JAK2 V617F mutation is a major diagnostic, therapeutic, and monitoring molecular target of Philadelphia-negative myeloproliferative neoplasms (MPNs). To date, numerous methods of detecting the JAK2 V617F mutation have been reported, but there is no gold-standard diagnostic method for clinical applications. Here, we developed and validated an efficient Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR associated protein 12a (Cas12a)-based assay to detect the JAK2 V617F mutation. Our results showed that the sensitivity of the JAK2 V617F/Cas12a fluorescence detection system was as high as 0.01%, and the JAK2 V617F/Cas12a lateral flow strip assay could unambiguously detect as low as 0.5% of the JAK2 V617F mutation, which was much higher than the sensitivity required for clinical application. The minimum detectable concentration of genomic DNA achieved was 0.01 ng/μL (~5 aM, ~3 copies/μL). In addition, the whole process only took about 1.5 h, and the cost of an individual test was much lower than that of the current assays. Thus, our methods can be applied to detect the JAK2 V617F mutation, and they are highly sensitive, rapid, cost-effective, and convenient.

CDs–MnO2–TPPS Ternary System for Ratiometric Fluorescence Detection of Ascorbic Acid and Alkaline Phosphatase

Manganese dioxide (MnO2) nanosheet-based fluorescence sensors often use oxidase-like activity or wide absorption spectrum for detection of antioxidants. In those strategies, MnO2 nanosheets were reduced to Mn2+ by antioxidants. However, few strategies emphasize the role of Mn2+ obtained from MnO2 reduction in the design of the fluorescence sensor. Herein, we expanded the application of a MnO2 nanosheet-based fluorescence sensor by involving Mn2+ in the detection process using ascorbic acid (AA) as a model target. In this strategy, carbon dots (CDs), MnO2 nanosheets, and tetraphenylporphyrin tetrasulfonic acid (TPPS) comprise a ternary system for ratiometric fluorescence detection of AA. Initially, CDs were quenched by MnO2 nanosheets based on the inner filter effect, while TPPS maintained its fluorescence intensity. After the addition of AA, MnO2 nanosheets were reduced to Mn2+ so that the fluorescence intensity of CDs was recovered and TTPS was quenched by coordination with Mn2+. Overall, AA triggered an emission intensity increase at 440 nm for CDs and a decrease at 640 nm for TPPS. The ratio intensity of CDs to TPPS (F440/F640) showed a good linear relationship from 0.5 to 40 μM, with a low detection limit of 0.13 μM for AA detection. By means of the alkaline phosphatase (ALP)-triggered generation of AA, this strategy can be applied for the detection of ALP in the range of 0.1–100 mU/mL, with a detection limit of 0.04 mU/mL. Furthermore, this sensor was applied to detect AA and ALP in real, complex samples with ideal recovery. This novel platform extended the application of MnO2 nanosheet-based fluorescence sensors.

A radiation tolerant laser-induced fluorescence detection system for a potential Europa Lander mission

Analytical techniques commonly implemented for in situ organic analysis on space missions lack the sensitivity or specificity necessary to definitively characterize key markers of current or past life, such as amino acids. To this end, our group has developed an analytical method for amino acid analysis at low parts-per-billion levels, utilizing capillary electrophoresis coupled to laser-induced fluorescence detection. Europa has been identified as a particularly appealing target for life detection, but its intense radiation environment presents additional challenges for instrument development and qualification. Here, we present work toward the development of a flight qualifiable laser-induced fluorescence detection system that could be implemented on potential future missions to the Jovian system which could experience total ionizing dose exposures of up to 300 krad. Our results show that a gallium nitride based laser diode and micro-photomultiplier based system can meet our system performance requirements under radiation conditions expected for a potential Europa Lander mission.

Usefulness of a Fluorescence Detection System for Intraoperative Identification of Parathyroid Adenoma

Usefulness of a Fluorescence Detection System for Intraoperative Identification of Parathyroid Adenoma

Development and Validation of an RP-HPLC-PDA Method for Determination of Paracetamol, Caffeine and Tramadol Hydrochloride in Pharmaceutical Formulations.

Paracetamol (acetaminophen) (PAR), caffeine (CAF) and tramadol hydrochloride (TRA) are important drugs widely used for many clinical purposes. Determination of their contents is of the paramount interest. In this respect, a quick, simple and sensitive isocratic RP-HPLC method with photodiode array detection was developed for the determination of paracetamol, caffeine and tramadol in pharmaceutical formulations. An improved sensitive procedure was also evolved for tramadol using a fluorescence detector system. A C18 column and a mobile phase constituted by methanol/phosphate were used. LODs were found to be 0.2 μg/mL, 0.1 μg/mL and 0.3 μg/mL for paracetamol, caffeine and tramadol hydrochloride, respectively, using photodiode-array detection. Alternatively, LOD for tramadol decreased to 0.1 μg/mL with the fluorescence detector. Other notable analytical figures of merit include the linear concentration ranges, 0.8–270 μg/mL, 0.4–250 μg/mL and 1.0–300 (0.2–40) μg/mL, for the same ordered analytes (including the fluorescence detector). The proposed method was successfully applied for the quantitative determination of the three drugs in tablet dosage forms.

Cyan-emitting silicon quantum dots as a fluorescent probe directly used for highly sensitive and selective detection of chlorogenic acid

As an important bioactive component in plants, chlorogenic acid (CGA) has been widely studied for its potential role in human health. In this work, cyan fluorescent silicon quantum dots were successfully synthesized via a simple one-pot method for the rapid detection of CGA. The optimal excitation and emission wavelength of the obtained SiQDs was 350 nm and 470 nm, respectively. When the CGA was added, the maximum emission intensity of the SiQDs can be effectively quenched due to dynamic and static mixed quenching mechanisms. More significantly, there was a remarkable linear correlation between fluorescence quenching efficiency and a broad concentration of CGA solution range from 10 to 150 μmol/L with a limit of detection (LOD) of 0.43 μmol/L. Furthermore, the proposed SiQDs were successfully applied to analyze CGA in coffee beans and instant coffee after simple pretreatment with satisfactory results. Based on these, a high sensitivity and excellent selectivity fluorescent probe detection system was constructed, and it provides a valuable platform for the detection of CGA and has broad application prospects in the biological and pharmaceutical analysis field.

Development of amplification system for point-of-care test of nucleic acid

Nucleic acid testing (NAT) has been widely used in many fields such as medical diagnosis, food safety testing and forensic identification. However, it can only be carried out in professional laboratory because the test process is complicated and rigorous. In this paper, a nucleic acid amplification system based on polymerase chain reaction (PCR) was developed to meet the requirements of point-of-care testing (POCT) for nucleic acids. Firstly, the mechanical structure and electronic control system were designed and constructed. Secondly, an integral separation PID algorithm for temperature control and an intelligent temperature compensation method based on support vector regression (SVR) were proposed. Finally, temperature measurement and biological experiments were performed to prove the stability and availability of the nucleic acid amplification system. The results showed that the system achieved a rapid temperature change velocity of 4.5 °C/s, and the steady-state error was within ± 0.5 °C. The nucleic acids in samples of different concentrations were well amplified, the system can be used for quantitative detection of nucleic acid with the help of a fluorescence detection system, and has higher sensitivity than Tianlong PCR instrument.