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1.
Pediatr Dent ; 42(3): 217-220, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32522326

RESUMO

Purpose: Early childhood caries remains a worldwide disease and often requires treatment under sedation or general anesthesia, with long waitlists. Silver diamine fluoride has been shown to arrest caries lesions. The purpose of this study was to determine whether silver diamine fluoride (SDF) application reduces emergency visits by waitlisted patients with early childhood caries (ECC). Methods: Waitlisted patients aged zero to 71 months with ECC who were treated with SDF were enrolled at the University of Florida's NCEF Pediatric Dental Center; their cumulative incidence of dental emergencies were compared with children who were waitlisted during the 16 months preceding the introduction of SDF. Data from patient records on demographics, dental visits, SDF placement, and caries arrest were abstracted. Bivariate analyses and multiple logistic regression modeling were performed. Results: Participants included 97 patients treated with SDF and 216 not treated with SDF. The cumulative incidence of dental emergencies was approximately 80 percent lower in the SDF group than in the comparison group (4.1 percent versus 17.6 percent; adjusted odds ratio equals 0.18; 95 percent confidence interval equals 0.06 to 0.54); 81 percent of SDF-treated surfaces were arrested at a follow-up visit. Conclusions: Silver diamine fluoride helps reduce emergency visits for children with early childhood caries while on treatment waitlists and confirms the effectiveness of SDF for caries arrest in primary teeth.


Assuntos
Cariostáticos , Cárie Dentária , Criança , Pré-Escolar , Emergências , Serviço Hospitalar de Emergência , Fluoretos Tópicos , Humanos , Lactente , Recém-Nascido , Compostos de Amônio Quaternário , Compostos de Prata
2.
Pediatr Dent ; 42(3): 221-225, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32522327

RESUMO

Purpose: The purpose of this study was to measure the shear bond strength (SBS) of glass ionomer cement (GIC) to artificial carious dentin with and without silver diamine fluoride (SDF) treatment. Methods: Permanent molars were sectioned and demineralized to create artificial carious lesions. In five groups, the demineralization of dentin, application of SDF, use of conditioner, and elapsed time between the placement of SDF and restoration were tested for differences in SBS using an UltraTester machine. Statistical analysis was done using the Kruskal-Wallis test and Tukey-Kramer multiple comparison tests. Results: The highest bond strength was found when GIC was placed on conditioned and demineralized dentin treated with SDF one week earlier. Treatment with SDF and use of conditioner did not statistically affect the SBS of GIC to demineralized dentin. Statistically significant increases in bond strength were found when one week elapsed between SDF application and GIC placement. The lowest bond strength was found with immediate GIC application onto SDF-treated demineralized dentin. Conclusions: These in vitro findings suggest that silver diamine fluoride treatment does not significantly affect the bond strength of glass ionomer cement to dentin lesions, and improved retention is obtained by allowing SDF solution to set for one week prior to GIC placement.


Assuntos
Colagem Dentária , Cárie Dentária , Dentina , Fluoretos Tópicos , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Compostos de Amônio Quaternário , Resistência ao Cisalhamento , Compostos de Prata
3.
Pediatr Dent ; 42(3): 226-231, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32522328

RESUMO

Purpose: American Academy of Pediatric Dentistry guidelines recommend treatment of primary teeth with 38 percent silver diamine fluoride (SDF) as a noninvasive option to arrest active dental caries lesions. A significant outcome of SDF treatment are lesions that clinically harden and become more resistant to further decay. Many practicing dentists believe that this increased hardening is due to the reaction of silver and fluoride with carious dentin. The purpose of this study was to focus on the structural and chemical effects of silver diamine fluoride treatment on the native tooth. Methods: In SDF-treated cavitated dentin lesions in teeth subsequently extracted for orthodontic reasons, the authors observed continuous, filamentous silver densities formed in situ from 50 to 2,100 µm in length and 0.25 to 7.0 µm in diameter using high-resolution synchrotron X-ray microcomputer tomography and field emission scanning electron microscopy. These "microwires" fill voids in the lesion caused by disease and permeate through surrounding dentinal tubules. Results: Spectroscopy confirmed that the chemical composition of the observed microwires is predominantly silver. Conclusions: These observations suggest mechanistic explanations for the structural reinforcement of carious dentin in addition to remineralization. It is hypothesized that silver diamine fluoride may achieve its antimicrobial functions by biochemical interactions and through its inherent ability to integrate into the native tooth structure.


Assuntos
Cárie Dentária , Cariostáticos , Criança , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata
4.
J Evid Based Dent Pract ; 20(1): 101422, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32381404

RESUMO

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: The effect of silver diamine fluoride in preventing caries in the primary dentition: a systematic review and meta-analysis. Oliveira BH, Rajendra A, Vietz-eenan A, Niederman R. Caries Res 2018;53(1):24-32. SOURCE OF FUNDING: Government: National Institute on Minority Health and Health Disparities of the National Institutes of Health under award no. R01MD011526 and U24MD006964, and Patient-Centered Outcomes Research Institute (PCORI) Award (PCS-1609-36824). The Teacher Training Program of the University of the State of Rio de Janeiro (Programa de Capacitação Docente da Universidade do Estado do Rio de Janeiro-PROCAD UERJ) also supported this work. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.


Assuntos
Cárie Dentária , Fluoretos , Cariostáticos , Fluoretos Tópicos , Humanos , Pintura , Compostos de Amônio Quaternário , Compostos de Prata , Dente Decíduo
5.
J Clin Pediatr Dent ; 44(2): 79-83, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271666

RESUMO

Objective: The study described the incidence of interproximal caries arrest following SDF and fluoride varnish application in the primary dentition. Study design: A retrospective analysis of dental records including radiographs was conducted for interproximal dental caries in pediatric patients treated with SDF applied with woven floss. Bitewing radiographs and ICCMS™ radiographic scoring criteria were used to assess caries depth in primary teeth at baseline and then at 12-month follow-up examination. Results: This study included 185 interproximal carious lesions in 131 patients treated with SDF. Mean baseline ICCMS™ score for all lesions was 1.50, with an average dmft of 2.9. The majority of carious lesions (n=155, 84.0%) showed radiographic evidence of non-progression at 12-month follow-up. There was no statistically significant difference in caries arrest among primary canines, primary first molars, and primary second molars (P=0.61). Furthermore, there was no statistically significant difference in caries arrest in patients with commercial insurance, Medicaid, or no insurance (P=0.27). Conclusions: SDF application with woven floss was associated with interproximal caries arrest in the primary dentition at 12-month follow-up in this sample of low caries risk children. Tooth type and insurance type were not associated with caries arrest.


Assuntos
Cárie Dentária , Cariostáticos , Criança , Fluoretos , Fluoretos Tópicos , Humanos , Pintura , Compostos de Amônio Quaternário , Estudos Retrospectivos , Compostos de Prata , Dente Decíduo
6.
J Adhes Dent ; 22(2): 161-172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32322837

RESUMO

PURPOSE: To evaluate 1. the microtensile bond strength (µTBS) and in situ degree of conversion (DC) of adhesives applied using two bonding strategies after silver diamine fluoride (diamine) application on carious dentinal lesions, and 2. dentin etching patterns using SEM and energy dispersive x-ray spectroscopy. MATERIALS AND METHODS: Human molars were randomly divided into 12 experimental groups according to: 1. application of a silver diamine fluoride solution (carious dentinal lesion without silver diamine fluoride treatment [control], with 12% silver diamine fluoride [diamine 12%] or 38% silver diamine fluoride [diamine 38%]); 2. adhesives (Clearfil Universal Bond Quick [CUQ] and Scotchbond Universal [SBU]); 3. adhesive strategy (etch-and-rinse [ER] and self-etch [SE]). After restoration, the specimens were sectioned and submitted to µTBS testing. Sticks from each tooth were used for DC evaluation. To examine the changes induced by diamine before and after phosphoric acid treatment, SEM/EDX analysis was performed. Data from the µTBS and DC tests were analyzed using three-way ANOVA and Tukey's test (α = 0.05). RESULTS: Both concentrations of diamine resulted in a statistically significantly higher mean µTBS compared to the control (p < 0.0001). Diamine 38% showed a statistically significantly higher mean µTBS for both adhesives in SE mode compared to diamine 12% (p < 0.0001). The application of diamine to carious dentinal lesions did not significantly influence the mean DC values for either adhesive (p = 0.72). SBU showed a higher mean DC compared to CUQ (p = 0.03). After diamine treatment, there was an increase in the Ca peak intensity and the presence of residual silver ions mainly when diamine 38% was applied along with the SE approach. CONCLUSION: Independent of the adhesive application approach, the use of diamine may be a promising alternative to increase µTBS without jeopardizing the DC of the two adhesives in carious dentinal lesions.


Assuntos
Colagem Dentária , Cimentos Dentários , Dentina , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata , Resistência à Tração
7.
J Dent Child (Chic) ; 87(1): 4-11, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32151304

RESUMO

Purpose: Current national evidence-based recommendations for treatment of carious lesions include the use of 38 percent silver diamine fluoride (SDF). The purpose of this study was to learn parents' opinions of esthetic changes to their children's teeth following treatment with SDF.
Methods: Three-hundred nineteen parents who had previously consented to SDF for caries arrest or caries prevention were asked if their child received SDF, if they noticed changes because of SDF, and how "bothered" they were by the changes.
Results: Two-hundred ten parents reported their child received SDF in the past 12 months, of whom 76 percent were confirmed by Codes on Dental Procedures and Nomenclature (CDT): 115 children received SDF for caries arrest and 45 received topical fluoride (SDF) for prevention. Of all 210 who reported SDF, 30 percent described discoloration of their child's teeth or gingiva. On a scale of zero (not bothered at all by changes due to SDF) to 10 (very bothered), parents' average rating was 1.2 ipoints; the average within the caries arrest group was 1.7.
Conclusion: Dental treatment requires a shared decision between parents and professionals, and follow-up regarding new procedures is warranted. In this study, treatment with SDF was well accepted by most parents.


Assuntos
Cárie Dentária , Fluoretos Tópicos , Cariostáticos , Criança , Humanos , Pais , Satisfação Pessoal , Compostos de Amônio Quaternário , Compostos de Prata
8.
J Clin Ethics ; 31(1): 68-73, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32213693

RESUMO

Digital medicine -- a drug delivered with an ingestion sensor and related data collection system -- has potential clinical value, especially for people whose lives are made more disorganized by poverty-related stress. It would be unjust if poor people were effectively barred from this treatment modality. Yet, unless a concerted effort is made to enable access through provision of smartphones to those who cannot afford them, this injustice will aggravate the digital divide in clinical care.


Assuntos
Tratamento Farmacológico , Monitorização Fisiológica , Justiça Social , Telemedicina , Disparidades em Assistência à Saúde , Humanos , Compostos de Prata
9.
Community Dent Health ; 37(2): 143-149, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32212436

RESUMO

INTRODUCTION: Silver diamine fluoride (SDF) is used to prevent and arrest caries across the globe, particularly in the developing world. Whilst its use in the Western World is increasing, it is not yet routinely used in the United Kingdom, nor is it advocated by our national guidelines. OBJECTIVES: To explore the literature surrounding the use of SDF, and consider the reasons why SDF has not yet been widely adopted in the United Kingdom (UK). DISCUSSION: There is a growing evidence base for the use of SDF for the arrest and prevention of dental caries in the primary and permanent dentition. Potential side effects include staining of carious tooth structure, but in some cases this is acceptable to parents. There is no evidence for the cost effectiveness of SDF, although it may be a reasonably cost-effective option. CONCLUSION: SDF is perhaps not yet widely adopted in the UK due to a perceived parental concern about its staining effect. With a growing evidence base and reportedly higher efficacy than fluoride varnish for caries prevention and arrest, SDF has the potential to play an important role in managing dental disease in children and young people in both primary and secondary care.


Assuntos
Cárie Dentária , Adolescente , Cariostáticos , Criança , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata , Dente Decíduo , Reino Unido
10.
Artigo em Inglês | MEDLINE | ID: mdl-32053040

RESUMO

The increased applications of nanomaterials in industry and biomedicine have resulted in a rising concern about their possible toxic impacts on living organisms. It has been claimed that the phytosynthesized nanomaterials have lower toxicity in comparison to their chemically synthesized counterparts. Therefore, it is important to evaluate their toxic effects on the environment. In the present study, we investigated the toxic effects of microwave-synthesized silver-reduced graphene oxide nanocomposites (MS-Ag-rGO) on Chlorella vulgaris. Algal cells were treated by 1, 2, 4 and 6 mg L-1 MS-Ag-rGO for 24 h. The obtained data with three replicates were examined using analysis of variance. Analysis of different growth parameters revealed that MS-Ag-rGO possessed significant dose-dependent toxic effect on C. vulgaris. Scanning electron microscope and fluorescence microscope images of the treated cells established morphological shrinkages and alteration in position of nucleoli. Moreover, reduction in the phenol and flavonoid contents, enhancement of H2O2 content, changes in the antioxidant enzymes activity and decreases in the growth parameters as well as photosynthetic pigments quantities confirmed the toxicity of MS-Ag-rGO to the C. vulgaris cells. Our findings revealed that MS-Ag-rGO possessed higher toxicity on C. vulgaris than Ag-rGO synthesized by hydrothermal technique.


Assuntos
Chlorella vulgaris/efeitos dos fármacos , Grafite/toxicidade , Microalgas/efeitos dos fármacos , Micro-Ondas , Nanocompostos/toxicidade , Prata/toxicidade , Chlorella vulgaris/ultraestrutura , Relação Dose-Resposta a Droga , Grafite/química , Química Verde , Peróxido de Hidrogênio/metabolismo , Microalgas/ultraestrutura , Nanocompostos/química , Óxidos , Prata/química , Compostos de Prata
11.
Compend Contin Educ Dent ; 41(2): 84-89; quiz 90, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32017586

RESUMO

Silver has a long history of use in medicine and dentistry, as its powerful antimicrobial properties have benefited mankind immensely. Silver formulations can be traced back to Hippocrates, and silver nitrate has centuries of use in medicine, including being utilized intraorally since at least the early 1800s. In the past roughly 40 years, silver diammine fluoride (SDF) has been used in many parts of the world to treat tooth sensitivity and for chemical attenuation of dental caries lesions. SDF was more recently introduced in North America for treatment of dental sensitivity with widespread off-label use as a dental caries infection inhibitor. Accordingly, SDF has been the subject of much dental research and many published articles in dentistry. In addition to providing significant chemical interference of progression of caries infections, SDF has the ability to prevent initiation of the caries process. This article gives a brief history of silver use in medicine and dentistry and documents a simplified procedure to saturate contacting proximal surfaces of teeth with 38% SDF solution, followed by fluoride varnish coverage, to prevent caries lesions and intercept progression of existing caries infections.


Assuntos
Cárie Dentária , Amônia , Cariostáticos , Odontologia , Fluoretos , Fluoretos Tópicos , Humanos , América do Norte , Compostos de Amônio Quaternário , Compostos de Prata
12.
Chem Commun (Camb) ; 56(15): 2300-2303, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31989132

RESUMO

A novel signal self-enhancement photoelectrochemical immuno-sensor has been developed based on the curing of sacrificial agent SO32- coated-Au NPs sensitizing Ag2S/CuS/α-Fe2O3 n-p-n hetero-structure films for the first time. This strategy has acquired high sensitivity and low background without addition of a sacrificial agent in solution in the detection of prostate antigen.


Assuntos
Técnicas Biossensoriais , Cobre/química , Técnicas Eletroquímicas , Compostos Férricos/química , Imunoensaio , Antígeno Prostático Específico/análise , Compostos de Prata/química , Humanos , Tamanho da Partícula , Processos Fotoquímicos , Soluções , Propriedades de Superfície
13.
J Agric Food Chem ; 68(7): 2124-2131, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31985223

RESUMO

Lignin acylated with acetate and/or p-coumarate is common in many herbaceous plants. Herein, the biomimetic oxidation of γ-acylated monolignols with Ag2O was studied to understand the effect of γ-acyl groups on monolignol polymerization. The oxidation of sinapyl acetate gave γ-acylated and α-acylated ß-O-4 dimers in 71 and 9.5% yields, respectively. The oxidation of sinapyl p-coumarate produced γ-acylated ß-O-4 and γ-acylated tetralin ß-ß dimers in 53 and 16% yields, respectively. Only the sinapyl alcohol moiety in sinapyl p-coumarate reacted, and the p-coumarate moiety remained unchanged, suggesting that p-coumaric acid is not incorporated into the lignin backbone in the acylated lignins. All of the γ-acylated monolignols used in this study produced the γ-acylated ß-O-4 dimers, which suggests that the γ-acylated monolignols act as lignin monomers. The relatively high yields of the ß-O-4 dimers indicate that Ag2O oxidation of the monolignols can be used as an easy method for synthesizing the ß-O-4 dimer model compounds.


Assuntos
Ácidos Cumáricos/química , Dioxanos/química , Lignina/química , Óxidos/química , Compostos de Prata/química , Acetatos/química , Biomimética , Oxirredução
14.
Br Dent J ; 228(2): 75-81, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31980777

RESUMO

Silver diamine fluoride (SDF) is a clear, odourless liquid indicated for desensitisation of non-carious tooth lesions and molar incisor hypomineralisation. It is also useful for arresting carious lesions in adults and children who are high caries-risk and/or have difficult-to-control, progressing carious lesions, those who are unable to tolerate invasive treatment, elderly populations, and those who are medically compromised or have additional care and support needs. SDF may be used to manage lesions that are too extensive to restore but not associated with pain and/or infection. This can be important particularly where extractions might be contra-indicated for medical or behavioural reasons. This paper summarises the global evidence for the effectiveness and safety of SDF, describes what it is, its mechanisms of action and presents recommendations on how to use it. There are details on indications/contra-indications and risks/benefits to be considered in the use of SDF also discussion of how to approach SDF's side effect of black staining of carious tooth tissue. We give an example of an information sheet (Appendix S1, see online supplementary information) that may be used when discussing SDF with patients, particularly for primary teeth in children, but adaptable for the permanent dentition and for adults.


Assuntos
Cariostáticos , Cárie Dentária , Adulto , Idoso , Criança , Fluoretos Tópicos , Humanos , Compostos de Amônio Quaternário , Compostos de Prata
15.
Dent Mater J ; 39(3): 407-414, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-31932548

RESUMO

The purpose of this study was to evaluate the effects of two different concentrations of silver diammine fluoride (SDF) on dentin bonding performance. Human mid-coronal dentin was treated with either distilled water (control), 3.8%SDF or 38%SDF for 3 min. A two-step self-etch adhesive and resin composite were applied according to manufacturer's instructions. After thermocycling (TC) at 0, 5,000 and 10,000 cycles, microtensile bond strength (µTBS) testing and morphological assessment of resin-dentin bonding interface were performed. At 0 TC, µTBSs of 3.8% and 38%SDF were significantly reduced (p<0.05). At 5,000 and 10,000 TC, µTBSs of 3.8%SDF were comparable to those of the control group, whereas the µTBSs of 38%SDF were significantly lower (p<0.05). Acid-base resistance zone formation was observed in all groups, however, slope-shaped formation was identified only in the SDF groups. The µTBSs and interfacial morphology were influenced by concentration of SDF and also TC.


Assuntos
Colagem Dentária , Adesivos Dentinários , Condicionamento Ácido do Dente , Amônia , Cimentos Dentários , Dentina , Fluoretos , Humanos , Teste de Materiais , Cimentos de Resina , Compostos de Prata , Resistência à Tração
16.
Int J Paediatr Dent ; 30(1): 85-95, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31419356

RESUMO

BACKGROUND: Silver diammine fluoride (SDF) applied before a restoration may prevent recurrent caries; therefore, its effect on the bonding of restorative materials is contradictory. AIM: To assess through a systematic review and meta-analysis the influence of SDF on the bonding performance of adhesive materials to dentine. DESIGN: A systematic search was carried out in PubMed, Web of Science, LILACS, and Scopus. Studies comparing bond strength of adhesive systems or glass ionomer cement to SDF-treated and -untreated (control) dentine were included. Global analysis comparing the bond strength data was performed, separately for adhesive systems and glass ionomer cement, using RevMan5.1, with a random-effect model, at a 5% significance level. RESULTS: Eleven studies were included in the review and ten in the meta-analyses. Overall pooled effect for glass ionomer cement has shown no significant difference between the groups (Z = 0.47; P = .64). SDF treatment significantly impairs the bonding of adhesive systems to dentine (Z = 2.11; P = .03); this effect can be eliminated by the rinsing step (Z = 0.85; P = .40). CONCLUSIONS: The previous application of SDF does not influence the dentine bond strength of glass ionomer cement, but compromises the bonding of adhesive systems.


Assuntos
Colagem Dentária , Cimentos de Ionômeros de Vidro , Amônia , Cimentos Dentários , Dentina , Fluoretos , Teste de Materiais , Cimentos de Resina , Compostos de Prata
17.
Chemistry ; 26(5): 1042-1051, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31614042

RESUMO

Following the recent discovery that traditional silver(I) oxide-promoted glycosidations of glycosyl bromides (Koenigs-Knorr reaction) can be greatly accelerated in the presence of catalytic TMSOTf, reported herein is a dedicated study of all major aspects of this reaction. A thorough investigation of numerous silver salts and careful refinement of the reaction conditions led to an improved mechanistic understanding. This, in turn, led to a significant reduction in the amount of silver salt required for these glycosylations. The progress of this reaction can be monitored by naked eye, and the completion of the reaction can be judged by the disappearance of characteristic dark color of Ag2 O. Further evidence on higher reactivity of benzoylated α-bromides in comparison to that of their benzylated counterparts has been acquired.


Assuntos
Ácidos/química , Glicosídeos/química , Brometos/química , Catálise , Glicosilação , Óxidos/química , Compostos de Prata/química
18.
J Food Sci ; 85(1): 209-219, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31830325

RESUMO

Salbutamol (SAL) can cause potential hazards to human health and its use as a growth promoter in meat-producing animals is illegal. This work reports a novel approach for competitive paper-based colorimetric immunoassay (PCI) using the Ag3 PO4 /Ag nanocomposite as label for sensitive and specific determination of SAL in flesh of swine and urine. The Ag3 PO4 /Ag nanocomposite was synthesized by a one-step chemical bath method, which could instantly oxidize a chromogenic substrate for the color development under acidic conditions without the participation of H2 O2 . This approach provides high affinity between the Ag3 PO4 /Ag nanocomposite and the substrate (with the Michaelis-Menten constant of 0.44 mM). In addition, the fabrication process of the PCI was simple and cost-effective. Particularly, the novel PCI also exhibits simplicity and cost-effectiveness of the fabrication process through a simple wax screen-printing, which requires inexpensive equipment and material including a screen, wax, a squeegee, and a hair dryer. Under optimal conditions, the competitive PCI exhibited a linearity range of 0.025 to 1.00 µg/L. The developed approach offers advantages over the conventional ELISA for the purpose of routine use because it requires a shorter incubation time (<1 hr), significantly small volumes of reagents and samples (<100 µL each), and an inexpensive consumer-grade digital camera coupled with a simple gray-scale transformation of the RGB (Red Green Blue) color image for the purpose of quantification of the detection. PRACTICAL APPLICATION: Salbutamol (SAL) can cause potential hazards to human health and the use of which as growth promoter in meat-producing animals is illegal. This work introduces a novel approach for competitive immunoassay on paper-based colorimetric immunoassay using the Ag3 PO4 /Ag nanocomposite as the label (instead of using natural enzyme) for low-cost, sensitive, and specific determination of SAL residues at low level in flesh of swine and urine samples. The proposed approach offers advantages over the conventional ELISA for the purpose of routine use.


Assuntos
Albuterol/urina , Colorimetria/métodos , Resíduos de Drogas/análise , Imunoensaio/métodos , Carne/análise , Animais , Contaminação de Alimentos/análise , Humanos , Nanocompostos/química , Fosfatos/química , Prata/química , Compostos de Prata/química , Suínos
19.
Environ Sci Pollut Res Int ; 27(1): 250-263, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31786759

RESUMO

Ketoconazole is an imidazole fungicide which is commonly used as pharmaceutical and healthcare products. Residual amount of this compound can cause adverse ecological health problems. The present study investigated ketoconazole photocatalytic degradation using Ag3PO4/graphene oxide (GO). Ag3PO4/GO and Ag3PO4 as visible light-driven photocatalysts was synthesized using the in situ growth method. Degradation of ketoconazole at the concentration of 1-20 mg/L in aqueous solutions was optimized in the presence of Ag3PO4/GO nanocomposite with the dosage of 0.5-2 g/L, contact time of 15-20 min, and pH of 5-9 using response surface methodology. A second-order model was selected as the best fitted model with R2 value and lack of fit as 0.935 and 0.06, respectively. Under the optimized conditions, the Ag3PO4/GO catalyst achieved a photocatalytic efficiency of 96.53% after 93.34 min. The photocatalytic activity, reaction kinetics, and stability were also investigated. The results indicated that the Ag3PO4/GO nanocomposite exhibited higher photocatalytic activity for ketoconazole degradation, which was 2.4 times that of pure Ag3PO4. Finally, a direct Z-scheme mechanism was found to be responsible for enhanced photocatalytic activity in the Ag3PO4/GO nanocomposite. The high photocatalytic activity, acceptable reusability, and good aqueous stability make the Ag3PO4/GO nanocomposite a promising nanophotocatalyst for photocatalytic degradation of azoles contaminants.


Assuntos
Grafite/química , Cetoconazol/química , Processos Fotoquímicos , Catálise , Luz , Nanocompostos/química , Fosfatos/química , Prata , Compostos de Prata/química
20.
Anal Chim Acta ; 1093: 43-51, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31735214

RESUMO

Efficient strategies in enhancing sensitivity are pivotal to ultrasensitive detection of tumor markers. In this work, based on the strategy of label-assisted chemical adsorption triggered conversion of electroactivity of sensing interface, a Ag/AgCl process was achieved to enhance sensitivity of the constructed sandwich-type amperometric immunosensor for ultrasensitive detection of carbohydrate antigen 19-9 (CA19-9). Briefly, polydopamine-Ag nanoparticles (PDA-Ag NPs), as signal precursor, combined with labeling antibody were served as labels and graphene oxide-melamine (GO-MA) substrate with chemical absorption capacity was applied as smart sensing interface. After successfully incubating labels, there was primitively no current response due to the poor conductivity between labels and electrode. However, in the presence of H2O2, Ag NPs from labels can be etched into Ag ions, which were adsorbed by GO-MA to form GO-MA-Ag as electroactive substrate. Then, the substrate exhibited a sharp and stable electrochemistry peak of solid-state Ag/AgCl process in the buffer containing KCl. The sensitivity toward detection of CA19-9 was notably enhanced based on the appearance of sharp peak. Under optimum conditions, the designed immunosensor demonstrated a wide working range from 0.0001 to 100 U mL-1 and an ultralow detection limit 0.032 mU mL-1. Thus, utilizing this strategy to construct immunosensor was highly promising in clinical diagnosis for ultrasensitive detection of tumor makers.


Assuntos
Biomarcadores Tumorais/sangue , Antígeno CA-19-9/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Nanopartículas Metálicas/química , Compostos de Prata/química , Adsorção , Anticorpos Imobilizados/imunologia , Biomarcadores Tumorais/imunologia , Técnicas Biossensoriais/métodos , Antígeno CA-19-9/imunologia , Técnicas Eletroquímicas/instrumentação , Eletrodos , Humanos , Indóis/química , Limite de Detecção , Polímeros/química , Reprodutibilidade dos Testes , Prata/química , Triazinas/química
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