Dispel some mist on circulating biopterins: measurement, physiological interval and pathophysiological implication.

BACKGROUND AND AIMS: Biopterins, including tetrahydrobiopterin (BH4), dihydrobiopterin (BH2), and biopterin (B), were crucial enzyme cofactors in vivo. Despite their recognized clinical significance, there remain notable research gaps and controversies surrounding experimental outcomes. This study aims to clarify the biopterins-related issues, including analytical art, physiological intervals, and pathophysiological implications. MATERIALS AND METHODS: A novel LC-MS/MS method was developed to comprehensively profile biopterins in plasma, utilizing chemical derivatization and cold-induced phase separation. Subsequently, apparently healthy individuals were enrolled to investigate the physiological ranges. And the relationships between biopterins and biochemical indicators were analyzed to explore the pathophysiological implications. RESULTS: The developed method was validated as reliable for detecting biopterins across the entire physiological range. Timely anti-oxidation was found to be essential for accurate assessment of biopterins. The observed overall mean ± SDs levels were 3.51 ± 0.94, 1.54 ± 0.48, 2.45 ± 0.84 and 5.05 ± 1.14 ng/mL for BH4, BH2, BH4/BH2 and total biopterins. The status of biopterins showed interesting correlations with age, gender, hyperuricemia and overweight. CONCLUSION: In conjunction with proper anti-oxidation, the newly developed method enables accurate determination of biopterins status in plasma. The observed physiological intervals and pathophysiological implications provide fundamental yet inspiring support for further clinical researches.

Fenton-like reaction triggered chemical redox-cycling signal amplification for ultrasensitive fluorometric detection of H2O2 and glucose.

An ultrasensitive fluorescent biosensor is reported for glucose detection based on a Fenton-like reaction triggered chemical redox-cycling signal amplification strategy. In this amplified strategy, Cu2+ oxidizes chemically o-phenylenediamine (OPD) to generate photosensitive 2,3-diaminophenazine (DAP) and Cu+/Cu0. On the one hand, the generated Cu0 catalyzes the oxidation of OPD. On the other hand, H2O2 reacts with Cu+ to produce hydroxyl radicals (˙OH) and Cu2+ through a Cu+-mediated Fenton-like reaction. The generated ˙OH and recycled Cu2+ ions take turns oxidizing OPD to produce more photoactive DAP, triggering a self-sustaining chemical redox-cycling reaction and a remarkable fluorescent enhancement. It is worth mentioning that the cascade reaction did not stop until OPD molecules were completely consumed. Benefiting from H2O2-triggered chemical redox-cycling signal amplification, the strategy was exploited for the development of an ultrasensitive fluorescent biosensor for glucose determination. Glucose content monitoring was realized with a linear range from 1 nM to 1 µM and a limit of detection of 0.3 nM. This study validates the practicability of the chemical redox-cycling signal amplification on the fluorescent bioanalysis of glucose in human serum samples. It is expected that the method offers new opportunities to develop ultrasensitive fluorescent analysis strategy.

Computational holographic ghost diffraction.

Since the paradigm shift in 2009 from pseudo-thermal ghost imaging (GI) to computational GI using a spatial light modulator, computational GI has enabled image formation via a single-pixel detector and thus has a cost-effective advantage in some unconventional wave bands. In this Letter, we propose an analogical paradigm known as computational holographic ghost diffraction (CH-GD) to shift ghost diffraction (GD) from classical to computational by using self-interferometer-assisted measurement of field correlation functions rather than intensity correlation functions. More than simply "seeing" the diffraction pattern of an unknown complex volume object with single-point detectors, CH-GD can retrieve the diffracted light field's complex amplitude and can thus digitally refocus to any depth in the optical link. Moreover, CH-GD has the potential to obtain the multimodal information including intensity, phase, depth, polarization, and/or color in a more compact and lensless manner.

ALP-assisted chemical redox cycling signal amplification for ultrasensitive fluorescence detection of DNA methylation.

Affinity assays allow direct detection of DNA methylation events without requiring a special sequence. However, the signal amplification of these methods heavily depends on nanocatalysts and bioenzymes, making them suffer from low sensitivity. In this work, alkaline phosphatase (ALP)-assisted chemical redox cycling was employed to amplify the sensitivity of fluorescence affinity assays for DNA methylation detection using Ru@SiO2@MnO2 nanocomposites as fluorescent probes. In the ALP-assisted chemical redox cycling reaction system, ALP hydrolyzed 2-phosphate-L-ascorbic acid trisodium salt (AAP) to produce AA, which could reduce MnO2 nanosheets to form Mn2+, making the fluorescence recovery of Ru@SiO2 nanoparticles possible. Meanwhile, AA was oxidized to dehydroascorbic acid (DHA), which was re-reduced by tris(2-carboxyethyl) phosphine (TCEP) to trigger a redox cycling reaction. The constantly generated AA could etch large amounts of MnO2 nanosheets and greatly recover Ru@SiO2 fluorescence, amplifying the signal of the fluorescence assay. Employing the proposed ALP-assisted chemical redox cycling signal amplification strategy, a sensitive affinity assay for DNA methylation detection was achieved using ALP encapsulated liposomes that were linked with the 5mC antibody (Ab) to bind with methylated sites. A detection limit down to 2.9 fM was obtained for DNA methylation detection and a DNA methylation level as low as 0.1% could be distinguished, which was superior to conventional affinity assays. Moreover, the affinity assays could detect DNA methylation more specifically and directly, implying their great potential for the analysis of tumor-specific genes in liquid biopsy.

A Fluorescence Turn On-off-on Method for Sensitive Detection of Sn2+ and Glycine Using Waste Eggshell Membrane Derived Carbon Nanodots as Probe.

Changes in Sn2+ and glycine levels are relevant to many important physiological procedures in human health. However, investigation of their physiological functions is limited because few versatile methods towards Sn2+ and glycine detection have been developed. In this work, a fluorescence turn on-off-on strategy was firstly constructed for rapid and sensitive detection of Sn2+ and glycine through the specific binding between Sn2+ and glycine. Carbon nanodots (CDs) with a quantum yield of 19.5% were synthesized by utilizing inner film of waste eggshell as carbon source and employed as fluorescent probe. In the presence of Sn2+, the fluorescence of CDs was quenched by Sn2+ via the primary inner filter effect (IFE). However, the binding between Sn2+ and glycine prevented the IFE between Sn2+ and CDs, resulting in fluorescence recovery of CDs. Under optimized conditions, the fluorescent response of CDs displayed good linear relationships with the concentrations of Sn2+ in the range of 10-200 µM and 200-5000 µM, and the limit of detection (LOD) was 2.4 µM. For glycine detection, a good linear relationship was obtained in the concentration range of 5-1000 µM with a low LOD down to 0.76 µM. Moreover, the practicability of the assay was also demonstrated by measuring glycine content in human serum samples. This work provides an economical, green and fast method for biological analysis of Sn2+ and glycine.

Development and evaluation of an external quality control and internal quality control containing real-time RT-PCR assay for the detection of o'nyong-nyong virus.

O'nyong-nyong fever is a mosquito-borne tropical viral disease while few molecular diagnostic tools have been established for its surveillance until now. In the current study, a single-step, dual-color real-time reverse transcription polymerase chain reaction (RT-PCR) assay which contained both external quality control (EQC) and internal quality control (IQC) prepared by armored RNA technique was developed and evaluated for the detection of o'nyong-nyong virus (ONNV). Results showed that the assay was established successfully without cross-reaction with genetically related or symptom-alike diseases, which showed high specificity of the assay. The coefficient of variation of the assay was 0.97%, far less than 5%, indicating good repeatability of the assay. The lower limit of detection of the assay could reach as low as 100 copies of genome equivalent. During evaluation, the assay could correctly detect ONNV from spiked human serum samples and Anopheles species mosquito samples, while no ONNV positive was observed either from serum samples of patients with acute febrile illness or from local Anopheles species mosquitoes, suggesting no ONNV had been transmitted locally. In conclusion, the assay could potentially provide a valuable platform for ONNV molecular detection, which may improve the preparedness for future o'nyong-nyong fever outbreaks.

Determination of trypsin using protamine mediated fluorescent enhancement of DNA templated Au nanoclusters.

A fluorescent method is described for trypsin determination through the strong electrostatic interactions between cationic polyelectrolytes and single-stranded DNA (ssDNA) templated Au nanoclusters (AuNCs). The ssDNA-AuNCs display improved fluorescence emission with excitation/emission maxima at 280/475 nm after being incorporated with poly(diallyldimethylammonium chloride) (PDDA). Fluorescent enhancement is mainly attributed to the electrostatic interactions occurring  between PDDA and ssDNA templates. This can make the conformation of the ssDNA templates to change. Thus, it offers a better microenvironment for stabilizing and protecting ssDNA-AuNCs, and results in fluorescence emission enhancement. By using protamine as a model, the method is employed for the determination of trypsin. The assay enables trypsin to be determined with good sensitivity and a linear response ranging from 5 ng⋅mL-1 to 60 ng⋅mL-1 with a 1.5 ng⋅mL-1 limit of detection. It is also extended to determine  the trypsin contents in human's serum samples with recoveries between 98.7% and 103.5% with relative standard deviations (RSDs) between 3.5% and 4.8%. A novel fluorescent strategy has been developed for of trypsin determination by using protamine mediated fluorescent enhancement of DNA templated Au nanoclusters.

Rapid Derivatization of Phenolic and Oxime Hydroxyl with Isonicotinoyl Chloride under Aqueous Conditions and Its Application in LC-MS/MS Profiling Multiclass Steroids.

Quantification of steroids possesses a crucial clinical value in early diagnosis and prognosis evaluation of various endocrine diseases. However, it is still challenging to realize feasible analysis of estrogens, androgens, progestogens, and corticoids within one single workflow. In this study, two derivatization reactions were newly designed for improvement: (1) acylation of phenolic hydroxyl on estrogens with isonicotinoyl chloride (INC) under the catalysis of 4-dimethylaminopyridine and (2) post-modification of oxime hydroxyl on hydroxylamine-pretreated ketosteroids with INC. Both reactions could conduct instantaneously at room temperature under aqueous conditions. Moreover, the resulting phenolic-INC and oxime-INC esters exhibited favorable MS responses. Through integrating these derivatization strategies with cold-induced phase separation technology, a feasible LC-MS/MS method was developed for simultaneous quantification of 15 multiclass steroids with proper sample consumption (50 µL serum), satisfying sensitivity (lower limit of quantitation at 0.01-5.00 ng/mL) and high throughput (40 min for sample-preparation). The practical applicability was tested by detecting 30 real samples from pregnant and non-pregnant women. The obtained results showed a good agreement with a previous validated methodology.

Icarisid II rescues cognitive dysfunction via activation of Wnt/ß-catenin signaling pathway promoting hippocampal neurogenesis in APP/PS1 transgenic mice.

Restoring the compromised neurogenesis has been served as a potential strategy to rescue cognitive dysfunction of Alzheimer's disease (AD). In this study, we explored whether icarisid II (ICS II), a natural product possessing powerful neuroprotection, could recover the neurogenesis dysfunction of APP/PS1 mice, and investigated its underlying mechanisms. Our results showed that oral administration of ICS II could alleviate cognitive injuries of APP/PS1 mice, promote hippocampal neurogenesis, as well as stimulate Wnt/ß-catenin signal pathway confirmed by upregulated Wnt-3a, phosphorylated glycogen synthase kinase-3ß (p-GSK-3ß), and ß-catenin. ICS II also depressed mitochondrial fission evidenced by upregulated Mitofusin 1 (Mfn 1) and Mitofusin 2 (Mfn 2), and downregulated mitochondrial fission 1 protein (Fis 1), mitochondrial fission factor (Mff), and phosphorylated dynamin-related protein 1 (p-Drp 1). However, these effects of ICS II were blunted by XAV-939, an inhibitor of Wnt/ß-catenin signaling pathway. In summary, our findings revealed that ICS II could improve neurogenesis and inhibit mitochondrial fission via activation of the Wnt/ß-catenin signaling pathway, which contributed to cognitive function restoration of APP/PS1 mice. This study discovered a novel mechanism involving neurogenesis regulation underlying the therapeutic effects of ICS II against AD.

Transcriptome Analysis of Apples in High-Temperature Treatments Reveals a Role of MdLBD37 in the Inhibition of Anthocyanin Accumulation.

Coloring in apple fruit due to anthocyanin accumulation is inhibited by high temperature; however, the underlying mechanism remains unclear. In the present study, total anthocyanin and cyanidin 3-galactoside contents were determined and compared between cv. 'Redchief Delicious' apple fruits at 25 °C and 35 °C treatments. The high temperature (35 °C) treatment substantially decreased total anthocyanin and cyanidin 3-galactoside contents. The transcriptomes of 25 °C- and 35 °C-treated apples were analyzed by high-throughput RNA sequencing. A total of 8354 differentially expressed genes (DEGs) were detected at four time points corresponding to the two temperature treatments. The up-regulated DEGs were annotated using GO as well as KEGG databases. A network module of 528 genes (including 21 transcription factors) most associated with the total anthocyanin and cyanidin 3-galactoside contents was constructed by weighted correlation network analysis (WGCNA). In the WGCNA module, we unearthed a LOB domain-containing gene designated as MdLBD37. The expression of MdLBD37 was sharply up-regulated by high temperature and negatively correlated with the total anthocyanin and cyanidin 3-galactoside contents. Overexpression of MdLBD37 in apple fruit and calli decreased the expression of anthocyanin biosynthetic genes, such as MdCHI, MdCHS, MdF3H, MdANS, MdDFR, and MdUFGT, along with anthocyanin accumulation. Our results suggested that MdLBD37 significantly influenced the high-temperature inhibition of anthocyanin accumulation in apples. The findings shed more light on the mechanism of anthocyanin inhibition during high-temperature stress in apples.

Ghost panorama using a convex mirror.

Computational ghost imaging or single-pixel imaging enables the image formation of an unknown scene using a lens-free photodetector. In this Letter, we present a computational panoramic ghost imaging system that can achieve a full-color panorama using a single-pixel photodetector, where a convex mirror performs the optical transformation of the engineered Hadamard-based circular illumination pattern from unidirectionally to omnidirectionally. To our best knowledge, it is the first time to propose the concept of ghost panoramas and realize preliminary experimentations. It is foreseeable that ghost panoramas will have more advantages in imaging and detection in many extreme conditions (e.g., scattering/turbulence and unconventional spectra), as well as broad application prospects.

The effect and mechanism of miR-607/CANT1 axis in lung squamous carcinoma.

Lung squamous carcinoma (LUSC) is the second most frequent subtype of non-small cell lung cancer. Rarely gene alterations are identified in LUSC. Therefore, identifying LUSC-related genes to explain the relevant molecular mechanism is urgently needed. A potential biomarker, calcium-activated nucleotidase 1 (CANT1), was elevated in tissues of LUSC patients relative to normal cases based on the TCGA and/or GTEx database. CCK-8 and transwell tests were then implemented to measure the proliferative, invasive and migratory capacities, and showed that knockdown of CANT1 blocked LUSC cells proliferation. miR-607, predicted as an upstream factor for CANT1, was declined in LUSC using TargetScan analysis and luciferase activity test. Low miR-607 expression was related with unfavorable outcomes of LUSC patients. Moreover, miR-607 downregulation elevated cell viability, invasion and migration in LUSC cells, which was antagonized by si-CANT1. GEPIA website was accessed to estimate the relevance between CANT1 and epithelial-mesenchymal transition (EMT)-related positive factors. The protein levels of Fibronectin, Vimentin, Snail and ß-catenin were altered due to the abnormal CANT1 and miR-607 expression. Together, these data unveiled that miR-607/CANT1 pair may exert a vital role in the progression of LUSC through mediating EMT process, which would furnish an available therapeutic therapy for LUSC.

Turning waste into treasure: chicken eggshell membrane derived fluorescent carbon nanodots for the rapid and sensitive detection of Hg2+ and glutathione.

Herein, a green, economical, and waste-utilization approach is reported for the synthesis of water-soluble carbon nanodots (C-Dots) with a high fluorescence quantum yield of 19.5%. As a common protein-rich waste, eggshell membrane was selected as a cost-effective and ideal precursor to prepare C-Dots using the microwave method. The as-prepared C-Dots showed a maximum emission at 375 nm with an excitation wavelength at 235 nm. The fluorescent C-Dots were adopted as a sensitive probe for the rapid detection of Hg2+ and glutathione (GSH) based on the fluorescence off and on (turn-off-on) strategy. This was ascribed to the fact that Hg2+ could effectively quench the fluorescence of the C-Dots and GSH was able to prevent fluorescence quenching owing to the specific binding between Hg2+ and GSH. The designed method exhibited a high sensitivity and selectivity towards the detection of Hg2+ and GSH. Under the optimized conditions, the method showed a good linear relationship with Hg2+ concentration in the range from 100 nM to 50 µM with a detection limit of 32.0 nM. For GSH detection, it displayed a linear range from 50 nM to 10 µM with a detection limit of 9.8 nM. Moreover, this method was successfully applied to detect GSH in human serum samples. The eggshell derived fluorescent C-Dots pave the way for economical environmental and biological analyses.

Quantum-illumination-inspired active single-pixel imaging with structured illumination.

Quantum-illumination-inspired single-pixel imaging (QII-SPI) or computational ghost imaging protocol is proposed to improve image quality in the presence of strong background and stray light. According to the reversibility of the optical path, a digital micro-mirror device acts as a structured light modulator and a spatial light filter simultaneously, which can effectively eliminate 50% of stray light. Accompanied by a 6 dB gain of detection signal-to-noise ratio under an equivalent loss condition, our scheme only requires a simple and minor modification on the placement of the single-pixel detector based on the original SPI system. Since QII-SPI will obtain almost the same reconstruction results as the passive SPI technology in principle, one can, therefore, adjust the placement position of the detector, without exchanging the relative position of the detector and the light source to realize the flexible conversion of the SPI system from active to passive. Also, this work initially discusses the influence of relative coherence time on Hadamard-based SPI driven by a thermal source. This work brings new insights into the optical path design of the SPI technology, paving the way for the practical application of active SPI in stray light environments.

Preventing forgery attacks in computational ghost imaging or disabling ghost imaging in a "spatiotemporal" scattering medium with weighted multiplicative signals.

The ghost imaging (GI) approach is an intriguing and promising image acquisition technique that can transmit high-quality image information in a scattering environment. In this paper, we focus on two concerns recently emerged in the GI modality: one is the vulnerability to forgery attacks in GI-based optical encryption [Opt. Lett.45, 3917 (2020)OPLEDP0146-959210.1364/OL.392424], and the other is the potential threat of GI to personal privacy regarding non-invasive imaging [Opt. Express28, 17232 (2020)OPEXFF1094-408710.1364/OE.391788]. The core idea is to recommend introducing weighted multiplicative signals [Opt. Express27, 36505 (2019)OPEXFF1094-408710.1364/OE.27.036505] into the computational GI system, whether on the transmitting end or the receiving end. At the transmitting end, the random multiplicative signal can be used as an additional key that can reduce the possibility of forgery attacks, thereby increasing image transmission security. On the receiving end, the introduction of a random multiplicative signal to a spatial scattering medium makes it a "spatiotemporal" scattering medium, whose transmittance changes with time. Further, the spatiotemporal scattering medium can disable direct imaging and GI at the same time with low cost, thereby having great potential in privacy protection in daily lives.

L-Histidine-DNA interaction: a strategy for the improvement of the fluorescence signal of poly(adenine) DNA-templated gold nanoclusters.

An interesting phenomenon is described that the fluorescence signal of poly(adenine) (A) DNA-templated gold nanoclusters (AuNCs) is greatly improved in the presence of L-histidine by means of L-histidine-DNA interaction. The modified nanoclusters display strong fluorescence emission with excitation/emission maxima at 290/475 nm. The fluorescence quantum yield (QY) is improved from 1.9 to 6.5%. Fluorescence enhancement is mainly ascribed to the L-histidine-DNA interaction leading to conformational changes of the poly(A) DNA template, which offer a better microenvironment to protect AuNCs. The assay enables L-histidine to be determined with good sensitivity and a linear response that covers the 1 to 50 nM L-histidine concentration range with a 0.3 nM limit of detection. The proposed method has been applied to the determination of imidazole-containing drugs in pharmaceutical samples. A turn-on fluorescent method has been designed for the sensitive detection of L-histidine as well as imidazole-containing drugs on the basis of the L-histidine-DNA interaction.

A turn-on fluorescence strategy for cellular glutathione determination based on the aggregation-induced emission enhancement of self-assembled copper nanoclusters.

As a class of ideal fluorescent nanomaterials, self-assembled copper nanoclusters (CuNCs) have attracted increasing interest. Unfortunately, most of these CuNCs only possessed bright luminescence in acidic solution, which limited their practical applications in a physiological environment. Retaining the strong fluorescence of these CuNCs in neutral or alkaline solution is still a challenging task. In this strategy, self-assembled CuNCs were prepared by using 4-methylthiophenol as the protecting ligand. The self-assembled CuNCs display stable and bright luminescence with excitation/emission maxima at 330/605 nm even in neutral and alkaline environments. Interestingly, with the addition of glutathione (GSH), the fluorescence intensity of CuNCs is enhanced strongly through the GSH-controlled aggregation-induced emission enhancement of self-assembled CuNCs. The turn-on fluorescence strategy can determine the GSH concentration in the range from 1 to 100 µM with a limit of detection of 300 nM. In addition, the method is employed for the determination of GSH levels in cells. Therefore, the turn-on fluorescence strategy is reliable, sensitive and suitable for the determination of cellular GSH levels.

A turn-on fluorescence strategy for biothiols determination by blocking Hg(II)-mediated fluorescence quenching of adenine-rich DNA-templated gold nanoclusters.

Fluorescent adenine (A)-rich DNA-templated gold nanoclusters were demonstrated to be a novel probe for determination of biothiols (including cysteine, glutathione, and homocysteine). Fluorescence intensity of adenine-rich DNA-templated gold nanoclusters could be greatly quenched by Hg(II) ions through the formation of a gold nanoclusters-Hg(II) system. When biothiols (cysteine as the model) were introduced into the system, the fluorescence intensity recovered due to the formation of a more stable Hg(II)-thiol coordination complex using Hg-S metal-ligand bonds, which inhibited the Hg(II)-mediated fluorescence quenching of adenine-rich DNA-templated gold nanoclusters. Based on this fluorescence phenomenon, an on-off-on fluorescence strategy was designed for the sensitive determination of biothiols. The method allowed sensitive detection of cysteine with a linear detection range from 100 nM to 5 µM and a limit of detection of 30 nM. Additionally, the assay can be applied for detection of biothiol levels in human plasma samples. Therefore, it can provide a simple and rapid fluorescent platform for biothiol detection.

Highly selective fluorimetric and colorimetric sensing of mercury(II) by exploiting the self-assembly-induced emission of 4-chlorothiophenol capped copper nanoclusters.

A highly stable copper nanoclusters (CuNC) carrying 4-chlorothiophenol as a protective ligand is described. They display self-assembly-induced emission with excitation/emission maxima at 330/605 nm even in neutral or alkaline aqueous environment. The fluorescence of these CuNC is quenched by Hg(II). Quenching is mainly ascribed to the formation of a complex formed via Hg-S bonding between the Hg(II) ions and the ligand. This destroys the ordered architectures of the assembled CuNC. The assay enables Hg(II) to be determined with good sensitivity and a linear response ranging from 1 to 500 nM Hg(II) with a 0.3 nM limit of detection. In addition, the method was implemented in a test strip (which undergoes a color change from red to blue) that can be used for visual determination of Hg(II) in complex environmental water samples. Graphical abstractNovel and highly selective fluorimetric and colorimetric methods have been designed for mercury(II) ions determination based on stable self-assembly-induced emission of copper nanoclusters.

Development and Evaluation of an iiPCR Assay for Salmonella and Shigella Detection on a Field-Deployable PCR System.

BACKGROUND: Salmonella and Shigella are often associated with fecal-oral transmission and cause large-scale outbreaks in centralized catering units and, therefore, should be frequently and strictly monitored, especially among food handlers. However, no specific and sensitive on-site detection method is available until now. METHODS: In this study, an insulated isothermal PCR assay for the detection of Salmonella and Shigella on a field-deployable PCR system was developed. Specificity, sensitivity, reproducibility, and clinical accuracy of the assay were characterized and evaluated. RESULTS: The insulated isothermal PCR assay could be completed within 58 minutes with minimal pretreatment needed. The assay was specific and with good reproducibility. The limit of detection was 103 CFU/mL and 101 CFU/mL for Salmonella and Shigella, respectively, which was comparable to multiplex real-time PCR. Mock on-site clinical evaluation results showed that the analytical sensitivity and specificity of the insulated isothermal PCR assay were 100% and 96.6%, while the positive predictive value and negative predictive value were 94.1% and 100%, respectively. CONCLUSION: Based on our results, we believe that the assay developed herein could serve as an alternative method for preliminary screening and provide a valuable platform for the on-site detection of Salmonella and Shigella, especially in resource-limited and developing countries.