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1.
Anal Chem ; 96(15): 5852-5859, 2024 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-38556977

RESUMO

A multicolor electrochemiluminescence (ECL) biosensor based on a closed bipolar electrode (BPE) array was proposed for the rapid and intuitive analysis of three prostate cancer staging indicators. First, [Irpic-OMe], [Ir(ppy)2(acac)], and [Ru(bpy)3]2+ were applied as blue, green, and red ECL emitters, respectively, whose mixed ECL emission colors covered the whole visible region by varying the applied voltages. Afterward, we designed a simple Mg2+-dependent DNAzyme (MNAzyme)-driven tripedal DNA walker (TD walker) to release three output DNAs. Immediately after, three output DNAs were added to the cathodic reservoirs of the BPE for incubation. After that, we found that the emission colors from the anode of the BPE changed as a driving voltage of 8.0 V was applied, mainly due to changes in the interfacial potential and faradaic currents at the two poles of the BPE. Via optimization of the experimental parameters, cutoff values of such three indicators at different clinical stages could be identified instantly with the naked eye, and standard precision swatches with multiple indicators could be prepared. Finally, in order to precisely determine the prostate cancer stage, the multicolor ECL device was used for clinical analysis, and the resulting images were then compared with standard swatches, laying the way for accurate prostate cancer therapy.


Assuntos
Técnicas Biossensoriais , Neoplasias da Próstata , Masculino , Humanos , Medições Luminescentes/métodos , Fotometria , Neoplasias da Próstata/diagnóstico , Antígeno Prostático Específico , DNA , Técnicas Biossensoriais/métodos , Eletrodos , Técnicas Eletroquímicas/métodos
2.
Medicine (Baltimore) ; 103(19): e37448, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38728494

RESUMO

BACKGROUND: Idiopathic gingival enlargement is associated with plaque, but other contributing factors are unclear. The prognosis of idiopathic gingival enlargement is closely related to the patient's oral hygiene habits and regular follow-up. CASE PRESENTATION: This article reports a case of a 32-year-old male patient with idiopathic gingival enlargement. The patient presented to the department of stomatology with a 2-month history of gingival swelling and pain on the right upper posterior teeth. During the treatment, oral hygiene instruction, supragingival cleaning, subgingival scaling, and root planning were carried out, and part of the hyperplastic gingiva was taken and sent for pathology. Pathological examination showed gingival enlargement with chronic suppurative inflammation. At 4-month follow-up, the patient's periodontal condition remained basically stable, and the gingival enlargement did not recur. CONCLUSION: The treatment of this case resulted in significant reduction of gingival swelling and patient's pain reduction through non-surgical treatment and good plaque control, indicating that patients with idiopathic gingival enlargement can also achieve ideal results through non-surgical treatment. Through oral hygiene instruction, the patient mastered the method of self-plaque control, which is conducive to the long-term stabilization of the periodontal situation.


Assuntos
Higiene Bucal , Humanos , Masculino , Adulto , Higiene Bucal/educação , Higiene Bucal/métodos , Raspagem Dentária/métodos , Hiperplasia Gengival/terapia , Aplainamento Radicular
3.
Toxics ; 12(2)2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38393220

RESUMO

Plastic additives that maintain integrity have been extensively studied for potential toxicity to fish; however, chemicals that protect polymers from (artificial) UV degradation are less studied. Benzotriazole UV stabilizers (BUVSs) are the most widely used UV stabilizers in plastics and are often used in sunscreens, cosmetics, paint, and food packaging. BUVSs can negatively affect aquatic wildlife when released into the environment via plastic degradation. In this review, we summarize the distribution of BUVSs globally and discuss neurotoxicological endpoints measured in fish to understand how these plastic additives can affect the neurological health of teleost fishes. BUVSs have been detected in aquatic environments at concentrations ranging from 0.05 up to 99,200 ng/L. Studies show that BUVSs affect behavioral responses and acetylcholinesterase activity, indicators of neurotoxicity. Our computational analysis using transcriptome data suggests certain pathways associated with neurodegeneration are responsive to exposure to BUVSs, like "Complement Activation in Alzheimer's Disease". Based on our review, we identify some research needs for future investigations: (1) molecular studies in the central nervous system to define precise mechanisms of neurotoxicity; (2) a wider range of tests for assessing aberrant behaviors given that BUVSs can affect the activity of larval zebrafish; and (3) histopathology of the nervous system to accompany biochemical analyses. These data are expected to enhance understanding of the neurotoxicity potential of benzotriazoles and other plastic additives.

4.
Int J Biol Macromol ; 269(Pt 1): 132083, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38705327

RESUMO

Arginine deiminase (ADI) has garnered significant interest because of its ability to objectively eradicate cancer cells and produce L-citrulline. To meet the production demands, this study focused on enhancing the enzyme activity and thermal stability of ADI. In this study, 24 ADI mutants were obtained through computer aid site-specific mutation in the ADI of Enterobacter faecalis. Notably, the specific enzyme activities of F44W, N163P, E220I, E220L, N318E, A336G, T340I, and N382F increased, reaching 1.33-2.53 times that of the original enzyme. This study confirmed that site-specific mutations are critical for optimizing enzyme function. Additionally, the F44W, N163P, E220I, T340I, and A336G mutants demonstrated good thermal stability. The optimal pH for mutant F44W increased to 8, whereas mutants E220I, I244V, A336G, T340I, and N328F maintained an optimal pH of 7.5. Conversely, the M109L, N163P, E220L, I244L, and N318E mutants shad an optimal pH of 7. This study revealed that mutant enzymes with increased activity were more likely to contain mutation sites situated near the four loops associated with catalytic residues, whereas mutations at the dimer junction sites had a higher tendency to enhance enzyme stability. These findings contribute to the development of ADI industrial applications and its modifications.


Assuntos
Estabilidade Enzimática , Hidrolases , Hidrolases/química , Hidrolases/genética , Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Mutação , Cinética , Engenharia de Proteínas/métodos , Biocatálise , Mutagênese Sítio-Dirigida , Modelos Moleculares , Temperatura
5.
J Agric Food Chem ; 72(10): 5379-5390, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38420706

RESUMO

3'-Sialyllactose (3'-SL) is among the foremost and simplest sialylated breast milk oligosaccharides. In this study, an engineered Escherichia coli for high-titer 3'-SL biosynthesis was developed by introducing a multilevel metabolic engineering strategy, including (1) the introduction of precursor CMP-Neu5Ac synthesis pathway and high-performance α2,3-sialyltransferase (α2,3-SiaT) genes into strain BZ to achieve de novo synthesis of 3'-SL; (2) optimizing the expression of glmS-glmM-glmU involved in the UDP-GlcNAc and CMP-Neu5Ac synthesis pathways, and constructing a glutamine cycle system, balancing the precursor pools; (3) analysis of critical intermediates and inactivation of competitive pathway genes to redirect carbon flux to 3'-SL biosynthesis; and (4) enhanced catalytic performance of rate-limiting enzyme α2,3-SiaT by RBS screening, protein tag cloning. The final strain BZAPKA14 yielded 9.04 g/L 3'-SL in a shake flask. In a 3 L bioreactor, fed-batch fermentation generated 44.2 g/L 3'-SL, with an overall yield and lactose conversion of 0.53 g/(L h) and 0.55 mol 3'-SL/mol, respectively.


Assuntos
Monofosfato de Citidina/análogos & derivados , Escherichia coli , Engenharia Metabólica , Ácidos Siálicos , Humanos , Escherichia coli/genética , Oligossacarídeos/metabolismo
6.
Int J Biol Macromol ; 259(Pt 2): 129316, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218286

RESUMO

Helicobacter pylori HpfutC, a glycosyltransferase (GT) 11 family glycoprotein, has great potential for industrial 2'-fucosyllactose (2'-FL) production. However, its limited catalytic activity, low expression, and poor thermostability hinder practical applications. Herein, a semi-rationally designed site-saturation mutation was applied to engineer the catalytic activity and thermostability of HpfutC. The 6 single point mutants (K102T, R105C, D115S, Y251F, A255G and K282E) and 6 combined mutants (V1, V2, V3, V4, V5, and V6) with enhanced enzyme activity were obtained by mutant library screening and ordered recombination mutation. The optimal mutant V6, with an optimum temperature of 40 °C, was not a metal-dependent enzyme, yet the reaction was facilitated by Mn2+. Compared to wild-type HpfutC, mutant V6 exhibited a 2.3-fold increase in specific activity and a 2.18-fold increase in half-life at 40 °C, respectively. Kinetic parameters indicated that the Km values of mutant V6 were 34.5 % (lactose) and 25.0 % (GDP-L-fucose) lower than those of the wild enzyme, whereas the kcat/Km values were 1.20 and 1.25-fold higher than those of the wild enzyme. Further, 3D-structure analysis revealed that the highly rigid structure, formation of new hydrogen bonds, increased hydrophobic residues and redistribution of electrostatic charges on the surface may be responsible for the elevated enzyme activity and thermostability. The strategy adopted in this study is of great significance to the solution of the technical bottleneck of HpfutC and the industrial application of 2'-FL.


Assuntos
Helicobacter pylori , Helicobacter pylori/metabolismo , Fucosiltransferases/genética , Fucosiltransferases/metabolismo , Mutação , Temperatura , Estabilidade Enzimática
7.
Coron Artery Dis ; 35(6): 451-458, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38595165

RESUMO

OBJECTIVES: This study aimed to analyze the ability of subendocardial viability ratio (SEVR) to predict the degree of coronary artery stenosis and the relationship between SEVR and the incidence of short-term cardiovascular endpoint events. METHOD: The indexes of 243 patients with chest pain were collected.. Binary logistic regression analyses were performed using the dichotomous outcome of high and non-high SYNTAX scores. Receiver operating characteristic curves were employed to comparatively analyze the diagnostic efficiencies of the indices and models. A survival analysis combined with the Cox regression analysis was performed using the Kaplan-Meier method to understand the relationship between the SEVR and the incidence of cardiovascular events within 1 year in patients with coronary heart disease (CHD). RESULTS: SEVR was significantly lower ( P  < 0.05) in the high-stenosis group than control and low-stenosis groups. The diagnostic efficacy of SEVR [area under the curve (AUC) = 0.861] was better than those of age (AUC = 0.745), ABI (AUC = 0.739), and AIx@HR75 (AUC = 0.659). The cutoff SEVR was 1.105. In patients with confirmed CHD who had been discharged from the hospital for 1 year, only SEVR affected survival outcomes (hazard ratio = 0.010; 95% confidence interval: 0.001-0.418; P  = 0.016). CONCLUSION: A significant decrease in SEVR predicted severe coronary artery stenosis, with a cutoff value of 1.105 and an accuracy of 0.861. In patients with CHD, the lower the SEVR, the higher was the rate of cardiovascular events at 1 year after hospital discharge.


Assuntos
Angiografia Coronária , Estenose Coronária , Valor Preditivo dos Testes , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Estenose Coronária/epidemiologia , Estenose Coronária/fisiopatologia , Estenose Coronária/diagnóstico , Estenose Coronária/complicações , Incidência , Angiografia Coronária/métodos , Idoso , Índice de Gravidade de Doença , Endocárdio/fisiopatologia , Curva ROC , Estudos Retrospectivos , Doença das Coronárias/epidemiologia , Doença das Coronárias/fisiopatologia , Prognóstico , Fatores de Risco
8.
PLoS One ; 19(4): e0302235, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38635544

RESUMO

INTRODUCTION: Physical exercise (PE) is essential for alleviating the symptoms of sarcopenia. Low motivation is a major barrier to PE. Mindfulness-based intervention (MBI) has the potential to improve motivation. However, few studies have used a mindfulness-based PE (MBPE) intervention among older people with sarcopenia. OBJECTIVES: To assess the feasibility, acceptability and preliminary effects of the MBPE program among community-dwelling older people with sarcopenia. METHODS AND ANALYSIS: A two-arm pilot randomised controlled trial will be conducted to assess the feasibility, acceptability and preliminary effects of an MBPE program among community-dwelling older people with sarcopenia. A total of 60 participants will be randomised into the intervention group, receiving the MBPE intervention twice a week over 12 weeks, or the control group, receiving health education with the same duration, number of sessions and frequency as the intervention group. Each session of the MBPE program will last about 60 min, including 5-10- min introduction, 20-min MBI, 30-min PE and 5-10-min sharing and discussion. The primary outcomes will be the feasibility (i.e., the time spent recruiting participants, the eligibility rate and the recruitment rate) and acceptability (i.e., the attendance rate, completion rate and attrition rate) of the MBPE program. The secondary outcomes will be the preliminary effects of the MBPE program on symptoms of sarcopenia, motivation for PE, psychological well-being, mindfulness level, physical activity level and quality of life. Individual interviews will be conducted to identify the strengths, limitations and therapeutic components of the intervention. The quantitative data will be analysed by generalised estimating equations. The qualitative data will be analysed by Braun and Clarke's thematic approach. CONCLUSION: The findings of this study will be able to provide evidence for the health professionals in adopting MBPE as a supportive intervention for the older adults with sarcopenia and the groundworks for the researchers in developing non-pharmacological intervention for older adults. The positive effects could facilitate healthy ageing and relief the burden of the medical system, especially in the countries facing the ageing population. TRIAL REGISTRATION NUMBER: NCT05982067; ClinicalTrials.gov.


Assuntos
Atenção Plena , Sarcopenia , Humanos , Idoso , Sarcopenia/terapia , Qualidade de Vida , Vida Independente , Estudos de Viabilidade , Projetos Piloto , Exercício Físico , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Clin Interv Aging ; 19: 1309-1323, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39050518

RESUMO

Objective: To explore the cut-off values and health evaluations of upper arm circumference (AC) and calf circumference (CC) on sarcopenia in Chinese community-dwelling older people. Methods: In this cross-sectional study, AC, CC, handgrip strength, muscle mass and gait speed were measured in 1537 Chinese community-dwelling older people in Sub-study 1. Correlation analysis, receiver operator characteristic curve (ROC curve) analysis, and consistency analysis were used for determination of AC and CC cut-off values for sarcopenia diagnosis (sarcopenia-AC and CC). Thereafter, 269 participants accepted additional assessments on physical function, body composition and muscle strength in Sub-study 2. T-test or Mann-Whitney U-test was used to explore the differential effects of sarcopenia-AC and CC on health indicators between sarcopenic and non-sarcopenic participants. Results: In Sub-study 1, the Area Under ROC (AUC) of AC and CC for sarcopenia screening were greater than 0.700 (P<0.05). The cut-off values, sensitivity and specificity of AC and CC on sarcopenia in males were 25.9 cm (86.0%, 83.6%) and 33.7 cm (90.7%, 81.4%) whereas in females were 26.5 cm (70.8%, 69.7%) and 33.0 cm (86.5%, 69.4%), respectively. In Sub-study 2, the participants with sarcopenia-AC or sarcopenia-CC showed lower muscle strength and lower fat and muscle mass than the ones without (P<0.05). Additionally, males instead of females with sarcopenia-AC or sarcopenia-CC showed worse performance in time-up and go test and 6-Minute Walk Test (P<0.05). However, the 30-second chair stand test was not different between participants with and without sarcopenia-AC or sarcopenia-CC in both sexes. Conclusion: We found accurate and Chinese population targeted cut-off values of AC and CC on sarcopenia diagnosis (25.9 cm and 33.7 cm in males; 26.5 cm and 33.0 cm in females) and a good evaluation effect of AC and CC on fat and muscle mass, muscle strength and physical functions in males, not females.


Assuntos
Braço , Força da Mão , Perna (Membro) , Sarcopenia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Braço/anatomia & histologia , Composição Corporal , China , Estudos Transversais , População do Leste Asiático , Avaliação Geriátrica/métodos , Perna (Membro)/anatomia & histologia , Força Muscular , Curva ROC , Sarcopenia/diagnóstico , Sarcopenia/fisiopatologia , Velocidade de Caminhada
10.
Biosens Bioelectron ; 253: 116162, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38437748

RESUMO

An electrochemiluminescence (ECL) biosensor with a pair of new ECL emitters and a novel sensing mechanism was designed for the high-sensitivity detection of microRNA-141 (miRNA-141). Sulfur-doped boron nitrogen quantum dots (S-BN QDs) were initially employed to modify the cathode of the bipolar electrode (BPE), while the anode reservoir was [Ir(dfppy)2(bpy)]PF6/TPrA system. The next step involved attaching H1-bound ultra-small WO3-x nanodots (WO3-x NDs) to the S-BN QDs-modified BPE cathode via DNA hybridization. A strong surface plasmon coupling (SPC) effect was observed between S-BN QDs and WO3-x NDs, which allowed for the enhancement of the red and visible ECL emission from S-BN QDs. After target-induced cyclic amplification to produce abundant Zn2+ and Au NPs-DNA3-Au NPs (Au NPs-S3-Au NPs), Zn2+ could cleave DNA at a nucleotide sequence-specific recognition site to release the WO3-x NDs, resulting in the first diminution of cathode ECL signal and the first enhancement of anode ECL signal. Moreover, the ECL signal at cathode decreased for the second time and the emission of [Ir(dfppy)2(bpy)]PF6 was continuously enhanced after the introduction of Au nanoparticles-S3-Au nanoparticles on the cathode surface. Our sensing mode with a dual "on-off" signal conversion strategy shows a good detection capability for miRNAs ranging from 10-17 to 10-10 M, with a limit of detection (LOD) as low as 10-17 M, which has great application potential in biomedical research and clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , MicroRNAs , Ouro , Boro , Transferência de Energia , Nitrogênio , Enxofre , DNA
11.
Int J Biol Macromol ; 276(Pt 2): 133875, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39019366

RESUMO

A novel biodegradable film was fabricated by incorporating bacterial nanocellulose stabilized valerian root extract (VRE) Pickering emulsion into karaya gum with better antioxidant and antibacterial properties for lamb meat preservation. The valerian root extract Pickering emulsion (VPE) exhibited 98 ± 1.84 % encapsulating efficiency and excellent physical stability with an average particle size of 274.6 nm. The incorporation of VPE-5 into the film matrix increased its elongation at break (EAB), and improved water resistance and barrier properties against oxygen, water vapor, and UV light. Moreover, the antioxidant and anti-bacterial properties against S.aerous and E. coli were also improved based on VPE-5 concentration. The SEM images showed a uniform distribution of VPE-5 while FTIR and XRD revealed its compatibility with karaya gum, which improved its thermal stability. The active films showed a significant preservative effect by reducing the pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and total viable count (TVC) value of lamb meat and maintained its texture and color during the storage period of 9 days at 4 °C. These results demonstrated the inclusion of VPE-5 into Karaya gum was a promising technique and offers a great potential application as a bioactive material in food packaging.


Assuntos
Celulose , Emulsões , Embalagem de Alimentos , Conservação de Alimentos , Goma de Karaya , Extratos Vegetais , Raízes de Plantas , Valeriana , Celulose/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Conservação de Alimentos/métodos , Raízes de Plantas/química , Embalagem de Alimentos/métodos , Animais , Valeriana/química , Goma de Karaya/química , Antioxidantes/farmacologia , Antioxidantes/química , Antibacterianos/farmacologia , Antibacterianos/química , Ovinos , Carne Vermelha/análise , Carne Vermelha/microbiologia , Escherichia coli/efeitos dos fármacos
12.
Clin Interv Aging ; 19: 265-276, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38384404

RESUMO

Purpose: This study aimed to establish equations for estimating muscle mass through anthropometric parameters or together with physical function parameters in the community-dwelling older adults, providing a simple way of muscle mass assessment. Methods: In this cross-sectional descriptive study, a total of 1537 older adults were recruited from the community and accepted the measurements of height, weight, upper arm and calf circumferences, grip strength, and walking speed. Body composition including appendicular skeletal muscle mass (ASM) was measured using bioelectrical impedance analysis (BIA). Participants were randomly divided into the development or validation group. Stepwise multiple linear regression was applied to develop equations in the development group. Thereafter, Pearson correlation coefficients, Bland-Altman plots, paired t-test, intraclass correlation coefficient (ICC) and paired-samples t-tests were used to assess the validity of the equations. Results: All parameters were significantly correlated with ASM (r = 0.195~0.795, P < 0.001) except for the age in the validation group (P = 0.746). The most optimal anthropometric equation was: [adjusted R2 = 0.911, standard error of the estimate (SEE) = 1.311, P < 0.001]. Comparatively speaking, this equation showed high correlation coefficient (r = 0.951, P < 0.001) and ICC (ICC = 0.950, P < 0.001). No significant differences were found between BIA-measured ASM and the estimated ASM. The Bland-Altman plot showed that the mean difference between the estimated ASM and BIA-measured ASM was 0 kg and the limits of agreement of ASM was -2.70~2.60 kg. Furthermore, inclusion of physical function did not significantly improve the adjusted R2 and SEE. Conclusion: The anthropometric equation offers a practical alternative simple and dependable method for estimating ASM in community-dwelling older adults.


Assuntos
Vida Independente , Músculo Esquelético , Humanos , Idoso , Índice de Massa Corporal , Músculo Esquelético/fisiologia , Estudos Transversais , Composição Corporal/fisiologia , Absorciometria de Fóton/métodos , China , Impedância Elétrica
13.
Anal Chim Acta ; 1315: 342822, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38879216

RESUMO

In this study, a novel electrochemiluminescence (ECL) biosensor was developed to detect microRNA-21 (miRNA-21) with high sensitivity by leveraging the combined mechanisms of resonance energy transfer (RET) and surface plasmon coupling (SPC). Initially, the glassy carbon electrode (GCE) were coated with Cu-Zn-In-S quantum dots (CZIS QDs), known for their defect-related emission suitable for ECL sensing. Subsequently, a hairpin DNA H3 with gold nanoparticles (Au NPs) attached at the end was modified over the surface of the quantum dots. The Au NPs could effectively quench the ECL signals of CZIS QDs via RET. Further, a significant amount of report DNA was generated through the action of a 3D DNA walker. When the report DNA opened H3-Au NPs, the hairpin structure experienced a conformational change to a linear shape, increasing the gap between the CZIS QDs and the Au NPs. Consequently, the localized surface plasmon resonance ECL (LSPR-ECL) effect replaced ECL resonance energy transfer (ECL-RET). Moreover, the report DNA was released following the addition of H4-Au NPs, resulting in the formation of Au dimers and a surface plasma-coupled ECL (SPC-ECL) effect that enhanced the ECL intensity to 6.97-fold. The integration of new ECL-RET and SPC-ECL biosensor accurately quantified miRNA-21 concentrations from 10-8 M to 10-16 M with a limit of detection (LOD) of 0.08 fM, as well as successfully applied to validate human serum samples.


Assuntos
Técnicas Biossensoriais , DNA , Técnicas Eletroquímicas , Medições Luminescentes , MicroRNAs , Pontos Quânticos , Ressonância de Plasmônio de Superfície , MicroRNAs/análise , MicroRNAs/sangue , Humanos , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , DNA/química , Pontos Quânticos/química , Ressonância de Plasmônio de Superfície/métodos , Medições Luminescentes/métodos , Ouro/química , Limite de Detecção , Transferência de Energia , Nanopartículas Metálicas/química
14.
Biosens Bioelectron ; 261: 116495, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38878699

RESUMO

In this study, we have for the first time constructed a ratiometric ECL biosensor for the ultrasensitive detection of microRNAs (miRNAs) using gold nanoparticles (Au NPs) to trigger both the low-potential emission from conjugated polymer poly(9,9-dioctylfluorene-2,7-diyl) dots (PFO Pdots) and the LSPR-ECL effect with sulfur-doped boron nitride quantum dots (S-BN QDs). PFO Pdots were first applied to the Au NPs-modified electrode, followed by covalent binding to capture the hairpin H1. Immediately thereafter, a small amount of miRNA-141 was able to generate a large amount of output DNA (OP) by traversing the target cycle. OP, H3-S-BN QDs, and H4-glucose oxidase (H4-GOD) were then added sequentially to the Au NPs-modified electrode surface, and the hybridization chain reaction (HCR) was initiated. This resulted in the introduction of a large amount of GOD into the system, which catalyzed the in situ formation of the co-reactant hydrogen peroxide (H2O2) from the substrate glucose. Due to the electron transfer effect, the production of H2O2 led to the ECL quenching of PFO Pdots. Meanwhile, H2O2 served as a co-reactant of S-BN QDs, resulting in strong ECL emission of S-BN QDs at the cathode. Furthermore, the cathodic ECL intensity of S-BN QDs was further enhanced by an LSPR-ECL mechanism between Au NPs and S-BN QDs. By measuring the ratio of ECL intensities at two excitation potentials, this approach could provide sensitive and reliable detection of miRNA-141 in the range of 0.1 fM ∼10 nM, with a detection limit of 0.1 fM.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Medições Luminescentes , Nanopartículas Metálicas , MicroRNAs , Pontos Quânticos , Técnicas Biossensoriais/métodos , Ouro/química , MicroRNAs/análise , Nanopartículas Metálicas/química , Pontos Quânticos/química , Técnicas Eletroquímicas/métodos , Humanos , Medições Luminescentes/métodos , Fluorenos/química , Glucose Oxidase/química , Peróxido de Hidrogênio/química
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