Effect of Short-term Deep Breathing Exercises on Perioperative Anxiety and Pain in Pediatric Orthopedic Patients: A Randomized Controlled Trial.

PURPOSE: There are currently no pediatric studies examining the effects of deep breathing on perioperative pain and anxiety. This study sought to determine the effect of short-term deep breathing exercises on perioperative anxiety and pain in pediatric patients and their parents. DESIGN: A randomized controlled trial was conducted in the Department of Orthopaedic Surgery where pediatric patients about to undergo surgery were allocated to a control group or a deep breathing group. In the intervention group, patients and their main guardian were guided to practice 10 minutes of deep breathing exercises twice a day for 3 to 4 days prior to surgery. Perioperative anxiety and pain were measured for both the children and parents as outcome indicators. METHODS: Perioperative anxiety was measured using the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF) and state anxiety was measured using the State-Trait Anxiety Inventory (STAI). Patients reported their pain levels daily using the Wong-Baker FACES Pain Rating Scale. The following cutoffs were determined as high levels of anxiety: STAI (adult) > 44, STAI (child) > 36, and mYPAS-SF ≥ 30. FINDINGS: No significant differences were found in the STAI, mYPAS-SF, and Wong-Baker FACES Pain Rating Scale scores of the patients between the intervention and control group. Overall statistics showed that parents had significantly higher postoperative state anxiety levels toward female children (44.93 ± 9.01) compared to male children (40.18 ± 9.89). Preoperative and postoperative parental state anxiety levels were correlated with the child's postoperative anxiety. Furthermore, children's postoperative state anxiety was slightly correlated with postoperative pain. CONCLUSIONS: Short-term use of our deep breathing exercises was ineffective in reducing incidences of perioperative pain and anxiety in pediatric orthopedic patients. A longer period of deep breathing administration may be required for the intervention to be effective. Parental anxiety may have an effect on anxiety levels in children, and postoperative parental anxiety may be affected by the gender of the child.

Dual isothermal amplification all-in-one approach for rapid and highly sensitive quantification of plasma circulating MYCN gene of neuroblastoma.

A dual isothermal amplification assay with dual fluorescence signal detection strategy, named dual isothermal amplification all-in-one approach, was developed for rapid, one-step, highly sensitive quantification of plasma circulating MYCN copy number of neuroblastoma (NB). The developed strategy consisted of rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) on a real-time PCR system using highly specific probe, molecular beacon (MB), as detection probe. The developed strategy possessing a broad linear dynamic range of 10 aM to 1 pM for both target gene (MYCN) and reference gene (NAGK). The ratio of the MYCN copy number to NAGK copy number (M/N ratio) was detected by the developed approach in cell lines, NB tumor tissues, hepatoblastoma tumor tissues and Wilms' tumor tissues, to which the M/N ratios were consistent with previous reports. In particular, the M/N ratio in NB clinical tissue specimens and NB plasma specimens detected with the developed approach were in keeping with the standard RT-PCR approach. More importantly, the M/N ratio in NB tissue samples and corresponding plasma samples of NB patients were consistent with each other with a correlation coefficient of 0.9690, indicating that plasma circulating MYCN is a promising indicator for the risk classification of NB.

Angiogenesis and anti-leukaemia activity of novel indole derivatives as potent colchicine binding site inhibitors.

The screened compound DYT-1 from our in-house library was taken as a lead (inhibiting tubulin polymerisation: IC50=25.6 µM, anti-angiogenesis in Zebrafish: IC50=38.4 µM, anti-proliferation against K562 and Jurkat: IC50=6.2 and 7.9 µM, respectively). Further investigation of medicinal chemistry conditions yielded compound 29e (inhibiting tubulin polymerisation: IC50=4.8 µM and anti-angiogenesis in Zebrafish: IC50=3.6 µM) based on tubulin and zebrafish assays, which displayed noteworthily nanomolar potency against a variety of leukaemia cell lines (IC50= 0.09-1.22 µM), especially K562 cells where apoptosis was induced. Molecular docking, molecular dynamics (MD) simulation, radioligand binding assay and cellular microtubule networks disruption results showed that 29e stably binds to the tubulin colchicine site. 29e significantly inhibited HUVEC tube formation, migration and invasion in vitro. Anti-angiogenesis in vivo was confirmed by zebrafish xenograft. 29e also prominently blocked K562 cell proliferation and metastasis in blood vessels and surrounding tissues of the zebrafish xenograft model. Together with promising physicochemical property and metabolic stability, 29e could be considered an effective anti-angiogenesis and -leukaemia drug candidate that binds to the tubulin colchicine site.

Efficacy and safety of vancomycin-loaded calcium sulfate versus conventional surgical debridement for pediatric acute osteomyelitis: a retrospective study.

BACKGROUND: The purpose of this study was to evaluate the safety and efficacy of vancomycin-loaded calcium sulfate beads and negative-pressure wound therapy (NPWT) in treating children with acute hematogenous osteomyelitis (AHOM). METHODS: A retrospective cohort study was conducted from January 2017 to January 2020 examining children (n = 60) with AHOM who were treated with surgical debridement followed by vancomycin-loaded calcium sulfate beads and NPWT (n = 32) and compared to treatment by conventional surgical debridement (n = 28) followed by NPWT. Conventional surgical treatment consisted of fenestration of necrotic infected bone, debridement of surrounding soft tissue, and washing of the medullary canal before the application of NPWT. In the vancomycin group, the antibiotic-loaded beads were implanted after washing the medullary canal and before the application of NPWT. Epidemiological factors, complications during the procedure, outcomes at last follow-up (30.0 ± 11.7 months, range 13-58 months), and laboratory parameters were documented and compared between the two groups. RESULTS: Good outcomes were achieved at last follow-up in 71.4% of the conventional treatment group and 75% of the vancomycin group. In the vancomycin group, it took a mean of 4.8 ± 2.5 days for CRP levels to decrease to 50% of initial inflammatory levels compared to 13 ± 9.6 days for the conventional treatment group (p = 0.001, t-test). The conventional group also had seven patients who underwent four or more surgeries whereas no patients in the vancomycin group underwent more than three surgeries (p = 0.013, chi-square test). CONCLUSION: Localized vancomycin delivery with NPWT effective for treating cases of AHOM that required. No perioperative adverse reactions or complications occurred from this treatment method. Based on the shortened recovery period of CRP levels, prolonged administration of post-operational parenteral antibiotics can possibly be reduced with this treatment method.

A hypothesis: Bitter taste receptors as a therapeutic target for the clinical symptoms of SARS-CoV-2.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has paralysed the livelihood of the global population by inflicting higher mortality among the affected patients. Nearly the entire human physiological system can get disrupted by the virulence of SARS-CoV-2, which exemplifies the significance of discovering a potential drug target. Similar to angiotensin-converting enzyme 2 (ACE2), bitter taste receptors (T2Rs) unequivocally expressed on all vital human organs, particularly on nasal/oral respiratory tract, gastrointestinal organs, innate immune cells, heart, brain and urogenital cells are susceptible to SARS-CoV-2 virulence. Activation of T2Rs by bitter agonists restores vital functions to these organs via activation of large conductance, Ca2+-dependent potassium (K+) channels (BKca), and inducible nitric oxide synthase. T2R activation in the gustatory system can act as the first defence mechanism, primarily preventing or mitigating SARS-CoV-2 entry to the respiratory tract. Moreover, T2R activation is crucial for the improved vasodilation accompanied by the attenuation of systemic inflammation; hyper-innate immune responses; gastrointestinal disorders; defective neurological functions; acute kidney injury; and impotency witnessed in severe SARS-CoV-2 cases. This review discusses the potential for bitter taste receptors to act as drug targets for SARS-CoV-2 symptoms and the use of existing bitter agonists to restore T2R function.

An efficient and universal In silico screening strategy for acquisition of high-affinity Aptamer and its application in analytical utility.

Numerous aptamers against various targets have been identified through the technology of systematic evolution of ligands by exponential enrichment (SELEX), but the affinity of these aptamers are often insufficient due to the limitations of SELEX. Therefore, a more rational in silico screening strategy (ISS) was developed for efficient screening of high affinity aptamers, which took shape complementarity and thermodynamic stability into consideration. Neuron specific enolase (NSE), a tumor marker, was selected as the target molecule. In the screening process, three aptamer candidates with good shape complementarity, lower ΔG values, and higher ZDOCK scores were produced. The dissociation constant (Kd) of these candidates to NSE was determined to be 10.13 nM, 14.82 nM, and 2.76 nM, respectively. Each of them exhibited higher affinity to NSE than the parent aptamer (Kd = 23.83 nM). Finally, an antibody-free fluorescence aptasensor assay, based on the aptamer with the highest affinity, P-5C8G, was conducted, resulting in a limit of detection (LOD) value of 1.8 nM, which was much lower than the parental aptamer (P, LOD = 12.6 nM). The proposed ISS approach provided an efficient and universal strategy to improve the aptamer to have a high affinity and good analytical utility.

A multiplex one-step fluorescence quantitative differential diagnosis method for severe hand, foot and mouth disease caused by coxsackievirus A16.

Hand foot and mouth disease (HFMD) is a common childhood infectious disease which is caused by human enterovirus. The objective of this study was to develop a rapid, sensitive, and accurate method for detecting severe HFMD caused by coxsackievirus A16 (CV-A16). A closed-tube sensitive multiplex one-step reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was applied to detect CV-A16 in the early stage of severe HFMD. This assay targeted the CV-A16 structure protein VP1 to distinguish CV-A16 from other coxsackieviruses The 5'UTR region of enteric viruses was used for detecting the enterovirus and ribonuclease P (RNaseP) was adopted as the internal reference gene. The multiplex MGB probe assay system was used to detect PCR amplicons with different fluorescence reporters in the same system. The limit of detection (LOD) of the RT-qPCR assay for the CV-A16 VP1 gene was 125.893 copies/µl, for the 5' UTR was 50.1187 copies/µl and for the RNaseP gene was 158.49 copies/µl. Furthermore, specificity analysis showed that the multiplex RT-PCR had no cross-reactivity with the influenza virus, herpangina virus and SARS-COV-2. In correlation analysis, the sensitivity of the multiplex RT-qPCR assay for CV-A16 detection was 100 % (288/288) and the specificity of the multiplex RT-qPCR assay was 99.94 % (3395/3397). The overall agreement between the multiplex RT-qPCR and the results of clinical diagnosis was 99.95 % (3683/3685) and kappa value was 0.996 (p<0.001). The entire procedure, from specimen processing to result reporting, could be completed within 1.5 hours. The one-step multiplex RT-qPCR assay for detecting CV-A16 developed in this study is a good laboratory diagnostic tool for rapid and reliable distinguished detection of CV-A16, especially for severe HFMD patients at an early stage in the disease with low virus load of CV-A16.

Clinical characteristics of neonatal and infant osteomyelitis and septic arthritis: a multicenter retrospective study.

OBJECTIVE: Signs and symptoms of osteomyelitis or septic arthritis in neonates and infants are often nonspecific and early-stage bone infections in infants may often go unnoticed. The objective of this study was to analyze the clinical characteristics of newborns and infants with osteomyelitis and septic arthritis to improve understanding of the disorder and to assist clinicians with diagnosis. METHODS: A retrospective multicenter study was conducted on neonates (0-28 days old, n = 94) and infants (1-12 months old, n = 415) with osteoarticular infections. Data consisting of clinical characteristics, complications, laboratory outcomes, and the pathogenic microorganisms causing osteomyelitis were tabulated. The statistics were further broken down into two regions and the significant differences between neonates and infants were evaluated and compared to the literature. RESULTS: Compared to infants, neonates had significantly lower incidences of fever (p < 0.0001), higher incidences of localized swelling (p = 0.0021), higher rate of infection at the humerus (p = 0.0016), higher percentage of Escherichia coli (p < 0.0001) and Klebsiella pneumoniae (p = 0.0039) infections, lower percentage of Staphylococcus aureus infections (p < 0.0001) and were more likely to develop septic arthritis (p < 0.0001). CONCLUSION: Distinct differences were found between neonatal and infants with osteoarticular infections. Future studies should focus on improving diagnosis and subsequent treatment regimens for younger age groups.

Anticancer therapy-induced adverse drug reactions in children and preventive and control measures.

In recent years, considerable achievements have been made in pediatric oncology with the innovation and development of antitumor drugs. However, compared to adults, children as a special group have not yet matured fully in terms of liver and kidney function. Moreover, pediatric patients are prone to more adverse drug reactions (ADRs) from the accumulation of antineoplastic drugs due to their smaller body size and larger body surface area. Chemotherapy-related ADRs have become a non-negligible factor that affects cancer remission. To date, studies on ADRs in pediatric cancer patients have emerged internationally, but few systematic summaries are available. Here, we reviewed the various systemic ADRs associated with antitumor drugs in children and adolescent patients, as well as the advances in strategies to cope with ADRs, which consisted of neurotoxicity, hematological toxicity, cardiotoxicity, ADRs of the respiratory system and gastrointestinal system and urinary system, ADRs of the skin and its adnexa, allergic reactions, and other ADRs. For clinicians and researchers, understanding the causes, symptoms, and coping strategies for ADRs caused by anticancer treatments will undoubtedly benefit more children.

Function and therapeutic prospects of next-generation probiotic Akkermansia muciniphila in infectious diseases.

Akkermansia muciniphila is a gram-negative bacterium that colonizes the human gut, making up 3-5% of the human microbiome. A. muciniphila is a promising next-generation probiotic with clinical application prospects. Emerging studies have reported various beneficial effects of A. muciniphila including anti-cancer, delaying aging, reducing inflammation, improving immune function, regulating nervous system function, whereas knowledge on its roles and mechanism in infectious disease is currently unclear. In this review, we summarized the basic characteristics, genome and phenotype diversity, the influence of A. muciniphila and its derived components on infectious diseases, such as sepsis, virus infection, enteric infection, periodontitis and foodborne pathogen induced infections. We also provided updates on mechanisms how A. muciniphila protects intestinal barrier integrity and modulate host immune response. In summary, we believe that A. muciniphila is a promising therapeutic probiotic that may be applied for the treatment of a variety of infectious diseases.

Functionalizing tetrahedral framework nucleic acids-based nanostructures for tumor in situ imaging and treatment.

Timely in situ imaging and effective treatment are efficient strategies in improving the therapeutic effect and survival rate of tumor patients. In recent years, there has been rapid progress in the development of DNA nanomaterials for tumor in situ imaging and treatment, due to their unsurpassed structural stability, excellent material editability, excellent biocompatibility and individual endocytic pathway. Tetrahedral framework nucleic acids (tFNAs), are a typical example of DNA nanostructures demonstrating superior stability, biocompatibility, cell-entry performance, and flexible drug-loading ability. tFNAs have been shown to be effective in achieving timely tumor in situ imaging and precise treatment. Therefore, the progress in the fabrication, characterization, modification and cellular internalization pathway of tFNAs-based functional systems and their potential in tumor in situ imaging and treatment applications were systematically reviewed in this article. In addition, challenges and future prospects of tFNAs in tumor in situ imaging and treatment as well as potential clinical applications were discussed.

An APE1 gated signal amplified biosensor driven by catalytic hairpin assembly for the specific imaging of microRNA in situ.

In situ imaging of microRNA (miRNA) content and distribution is valuable for monitoring tumor progression. However, tumor specific in situ imaging remains a challenge due to low miRNA abundance, lack of biological compatibility, and poor specificity. In this study, we designed a DNA tetrahedral framework complex with hairpins (DTF-HPAP) consisting of an apurinic/apyrimidinic site (AP site) that could be specifically recognized and cleaved by apurinic/apyrimidinic endonuclease 1 (APE1). Efficient and specific in situ imaging of miR-21 in tumors was thus achieved through catalytic hairpin assembly (CHA) reaction. In this study, DTF-HPAP was successfully constructed to trigger the cumulative amplification of fluorescence signal in situ. The specificity, sensitivity and serum stability of DTF-HPAP were verified in vitro, and DTF-HPAP could be easily taken up by cells, acting as a biosensor to detect tumors in mice. Furthermore, we verified the ability of DTF-HPAP to specifically image miR-21 in tumors, and demonstrated its capability for tumor-specific imaging in clinical samples.

Relationship between biofilm formation and antibiotic resistance of Klebsiella pneumoniae and updates on antibiofilm therapeutic strategies.

Klebsiella pneumoniae is a Gram-negative bacterium within the Enterobacteriaceae family that can cause multiple systemic infections, such as respiratory, blood, liver abscesses and urinary systems. Antibiotic resistance is a global health threat and K. pneumoniae warrants special attention due to its resistance to most modern day antibiotics. Biofilm formation is a critical obstruction that enhances the antibiotic resistance of K. pneumoniae. However, knowledge on the molecular mechanisms of biofilm formation and its relation with antibiotic resistance in K. pneumoniae is limited. Understanding the molecular mechanisms of biofilm formation and its correlation with antibiotic resistance is crucial for providing insight for the design of new drugs to control and treat biofilm-related infections. In this review, we summarize recent advances in genes contributing to the biofilm formation of K. pneumoniae, new progress on the relationship between biofilm formation and antibiotic resistance, and new therapeutic strategies targeting biofilms. Finally, we discuss future research directions that target biofilm formation and antibiotic resistance of this priority pathogen.

P2Y6R: A Promising New Target in Inflammatory Diseases and Advances in its Antagonists.

P2Y receptors (P2YRs) are G protein-coupled receptors that are activated by extracellular nucleotides. The P2Y6 receptor (P2Y6R) is specifically activated by UDP, causing PKC activation and intracellular calcium ion release through the PLC pathway. Based on receptor tissue distribution and related pathways, several studies have reported that P2Y6R plays a physiological role in mediating inflammation, which suggests that P2Y6R could be a promising molecular target for the treatment of inflammatory diseases. In the past ten years, several P2Y6R antagonists have been discovered as new therapeutic strategies for inflammatory diseases. In this article, we systematically summarize the role of P2Y6R in inflammation and highlight the anti-inflammatory mechanism of a key P2Y6R antagonist, MRS2578. Insight into recent progress on the discovery of P2Y6R antagonists is also discussed.

Clinical Associations of Bitter Taste Perception and Bitter Taste Receptor Variants and the Potential for Personalized Healthcare.

Bitter taste receptors (T2Rs) consist of 25 functional receptors that can be found in various types of cells throughout the human body with responses ranging from detecting bitter taste to suppressing pathogen-induced inflammation upon activation. Numerous studies have observed clinical associations with genetic or phenotypic variants in bitter taste receptors, most notably that of the receptor isoform T2R38. With genetic variants playing a role in the response of the body to bacterial quorum-sensing molecules, bacterial metabolites, medicinal agonists and nutrients, we examine how T2R polymorphisms, expression levels and bitter taste perception can lead to varying clinical associations. From these genetic and phenotypic differences, healthcare management can potentially be individualized through appropriately administering drugs with bitter masking to increase compliance; optimizing nutritional strategies and diets; avoiding the use of T2R agonists if this pathway is already activated from bacterial infections; adjusting drug regimens based on differing prognoses; or adjusting drug regimens based on T2R expression levels in the target cell type and bodily region.

Plasma circulating cell-free MYCN gene: A noninvasive and prominent recurrence monitoring indicator of neuroblastoma.

The postoperative recurrence of neuroblastoma (NB) patients is an essential reason for the high mortality of NB due to the lack of early, non-invasive, and dynamic strategies for monitoring NB recurrence. Therefore, whether the plasma circulating cell-free MYCN gene as an indicator for monitoring of NB recurrence was systematically evaluated. The MYCN copy number and NAGK (reference gene) copy number (M/N) ratio in plasma and corresponding tumor tissues of NB patients was detected using an economical, sensitive, and specific single-tube dual RT-PCR approach developed in this study. The plasma M/N ratio of the MYCN gene amplification (MNA) group (N = 25, median M/N ratio = 4.90) was significantly higher than that of the non-MNA group (N = 71, median M/N ratio = 1.22), p < .001. The M/N ratio in NB plasma (N = 60) was positively correlated with the M/N ratio in NB tumor tissue (N = 60), with a correlation coefficient of 0.9496. In particular, the results of dynamic monitoring of postoperative plasma M/N ratio of NB patients showed that an abnormal increase in M/N ratio could be detected 1-2 months before recurrence in NB patients. In summary, the single-tube double RT-PCR approach can be used to quantitatively detect MYCN copy number. The copy number of MYCN in the tissue and plasma of NB patients is consistent with each other. More importantly, the circulating cell-free MYCN gene of NB patients can be used as a monitoring indicator for early, non-invasive, and dynamic monitoring of NB recurrence.

Global spread of carbapenem-resistant Enterobacteriaceae: Epidemiological features, resistance mechanisms, detection and therapy.

Bacterial drug resistance has become a global public health threat, among which the infection of carbapenem-resistant Enterobacterales (CRE) is one of the top noticeable issues in the global anti-infection area due to limited therapy options. In recent years, the prevalence of CRE transmission around the world has increased, and the transmission of COVID-19 has intensified the situation to a certain extent. CRE resistance can be induced by carbapenemase, porin, efflux pump, penicillin-binding protein alteration, and biofilm production. Deletion, mutation, insertion, and post-transcriptional modification of corresponding coding genes may affect the sensitivity of Enterobacterales bacteria to carbapenems. Clinical and laboratory methods to detect CRE and explore its resistance mechanisms are being developed. Due to the limited options of antibiotics, the clinical treatment of CRE infection also faces severe challenges. The clinical therapies of CRE include single or combined use of antibiotics, and some new antibiotics and treatment methods are also being developed. Hence, this review summarizes the epidemiology, resistance mechanisms, screening and clinical treatments of CRE infection, to provide references for clinical prevention, control and treatment of CRE infection.

Joint analysis of the metabolomics and transcriptomics uncovers the dysregulated network and develops the diagnostic model of high-risk neuroblastoma.

High-risk neuroblastoma (HR-NB) has a significantly lower survival rate compared to low- and intermediate-risk NB (LIR-NB) due to the lack of risk classification diagnostic models and effective therapeutic targets. The present study aims to characterize the differences between neuroblastomas with different risks through transcriptomic and metabolomic, and establish an early diagnostic model for risk classification of neuroblastoma.Plasma samples from 58 HR-NB and 38 LIR-NB patients were used for metabolomics analysis. Meanwhile, NB tissue samples from 32 HR-NB and 23 LIR-NB patients were used for transcriptomics analysis. In particular, integrative metabolomics and transcriptomic analysis was performed between HR-NB and LIR-NB. A total of 44 metabolites (P < 0.05 and fold change > 1.5) were altered, including 12 that increased and 32 that decreased in HR-NB. A total of 1,408 mRNAs (P < 0.05 and |log2(fold change)|> 1) showed significantly altered in HR-NB, of which 1,116 were upregulated and 292 were downregulated. Joint analysis of both omic data identified 4 aberrant pathways (P < 0.05 and impact ≥ 0.5) consisting of glycerolipid metabolism, retinol metabolism, arginine biosynthesis and linoleic acid metabolism. Importantly, a HR-NB risk classification diagnostic model was developed using plasma circulating-free S100A9, CDK2, and UNC5D, with an area under receiver operating characteristic curve of 0.837 where the sensitivity and specificity in the validation set were both 80.0%. This study presents a novel pioneering study demonstrating the metabolomics and transcriptomics profiles of HR-NB. The glycerolipid metabolism, retinol metabolism, arginine biosynthesis and linoleic acid metabolism were altered in HR-NB. The risk classification diagnostic model based on S100A9, CDK2, and UNC5D can be clinically used for HR-NB risk classification.

Six-Year Follow-Up of a Rare Bifid Talus and Eight-Toed Central Polydactyly: A Case Report.

Eight-toed central polydactyly is a rare congenital foot deformity and no other case with a bifid talus has been reported in the literature. We present a 6-year follow-up of a male child who had eight-toed central polydactyly with a duplicate cuneiform bone and bifid talus in his right foot. During preoperative planning, CT scans were conducted to evaluate the duplicate tarsals and to assist in reaching surgical decisions. In 2013, when the child was 1 year and 8 months old, the fourth, fifth and sixth phalanges and metatarsals as well as the duplicate cuneiform bone were excised. A portion of the malformed talus was also resected. This case report discusses functional and aesthetic outcomes after 6 years and provides an analysis on relevant reconstructive follow-up practices.

Rapid electrochemical quantification of trace Hg2+ using a hairpin DNA probe and quantum dot modified screen-printed gold electrodes.

Rapid, simple, sensitive and specific approaches for mercury(ii) (Hg2+) detection are essential for toxicology assessment, environmental protection, food analysis and human health. In this study, a ratiometric hairpin DNA probe based electrochemical biosensor, which relies on hairpin DNA probes conjugated with water-soluble and carboxyl functionalized quaternary Zn-Ag-In-S quantum dot (QD) on screen-printed gold electrodes (SPGE), referred to as the HP-QDs-SPGE electrochemical biosensor in this study, was developed for Hg2+ detection. Based on the "turn-off" reaction of a hairpin DNA probe binding with a mismatched target and Hg2+ through the formation of T-Hg2+-T coordination, the HP-QDs-SPGE electrochemical biosensor can rapidly quantify trace Hg2+ with high ultrasensitivity, specificity, repeatability and reproducibility. The conformational change of the hairpin DNA probe caused a significant decrease in electrochemical intensity, which could be used for the quantification of Hg2+. The linear dynamic range and high sensitivity of the HP-QDs-SPGE electrochemical biosensor for the detection of Hg2+ was studied in vitro, with a broad linear dynamic range of 10 pM to 1 µM and detection limits of 0.11 pM. In particular, this HP-QDs-SPGE electrochemical biosensor showed excellent selectivity toward Hg2+ ions in the presence of other metal ions. More importantly, this biosensor has been successfully used to detect Hg2+ in deionized water, tap water, groundwater and urine samples with good recovery rate and small relative standard deviations. In summary, the developed HP-QDs-SPGE electrochemical biosensor exhibited promising potential for further applications in on-site analysis.