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1.
Anal Chim Acta ; 1307: 342630, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38719407

ABSTRACT

BACKGROUND: MicroRNAs, as oncogenes or tumor suppressors, enable to up or down-regulate gene expression during tumorigenesis. The detection of miRNAs with high sensitivity is crucial for the early diagnosis of cancer. Inspired by biological ion channels, artificial nanochannels are considered as an excellent biosensing platform with relatively high sensitivity and stability. The current nanochannel biosensors are mainly based on homogeneous membranes, and their monotonous structure and functionality limit its further development. Therefore, it is necessary to develop a heterostructured nanochannel with high ionic current rectification to achieve highly sensitive miRNA detection. RESULTS: In this work, an asymmetric heterostructured nanochannel constructed from dendrimer-gold nanoparticles network and anodic aluminum oxide are designed through an interfacial super-assembly method, which can regulate ion transport and achieve sensitive detection of target miRNA. The symmetry breaking is demonstrated to endow the heterostructured nanochannels with an outstanding ionic current rectification performance. Arising from the change of surface charges in the nanochannels triggered by DNA cascade signal amplification in solution, the proposed heterogeneous nanochannels exhibits excellent DNA-regulated ionic current response. Relying on the nucleic acid's hybridization and configuration transformation, the target miRNA-122 associated with liver cancer can be indirectly quantified with a detection limit of 1 fM and a wide dynamic range from 1 fM to 10 pM. The correlation fitting coefficient R2 of the calibration curve can reach to 0.996. The experimental results show that the method has a good recovery rate (98%-105 %) in synthetic samples. SIGNIFICANCE: This study reveals how the surface charge density of nanochannels regulate the ionic current response in the heterostructured nanochannels. The designed heterogeneous nanochannels not only possess high ionic current rectification property, but also enable to induce superior transport performance by the variation of surface chemistry. The proposed biosensor is promising for applications in early diagnosis of cancers, life science research, and single-entity electrochemical detection.


Subject(s)
Aluminum Oxide , Biosensing Techniques , Dendrimers , Gold , MicroRNAs , MicroRNAs/analysis , Gold/chemistry , Dendrimers/chemistry , Aluminum Oxide/chemistry , Humans , Biosensing Techniques/methods , Metal Nanoparticles/chemistry , Limit of Detection , Electrochemical Techniques/methods , Nanostructures/chemistry
2.
Talanta ; 275: 126155, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38678928

ABSTRACT

Developing portable and sensitive biosensors for bacteria detection is highly demanded due to their association with environmental and food safety. Paper-based microfluidic chip is the suitable candidate for constructing pump-free biosensor since paper is hydrophilic, low-cost and easy to use. However, the contradiction between sensitivity and small sample volume seriously affects the application of paper-based chip for bacteria detection. Here, a new microfluidic biosensor, combining large PDMS reservoir for sample storage, hydrophilic paper substrate for pump-free water transport, coated microspheres for bacteria capture and super absorbent resin for water absorption, is designed for the detection of bacteria in aqueous samples. Once the sample solution is introduced in the reservoir, water will automatically flow through the gaps between microspheres and the target bacteria will be captured by the aptamer coated on the surface. To facilitate PDMS reservoir bonding and ensure water transport, the upper side of paper substrate is coated with Polyethylenimine modified PDMS and the bottom side is kept unchanged. After all the solution is filtrated, fluorescent dye strained bacteria are enriched on the microspheres. The fluorescent intensity representing the number of bacteria captured is then measured using a portable instrument. Through the designed microfluidic biosensor, the bacteria detection can be achieved with 2 mL sample solution in less than 15 min for water or 20 min for diluted milk. A linear range from 10 CFU/mL to 1000 CFU/mL is obtained. The paper-based 3D biosensor has the merits of low-cost, simple operation, pump-free and high sensitivity and it can be applied to the simultaneous detection of multiple bacteria via integrating different aptamers.


Subject(s)
Biosensing Techniques , Dimethylpolysiloxanes , Lab-On-A-Chip Devices , Paper , Dimethylpolysiloxanes/chemistry , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Bacteria/isolation & purification , Aptamers, Nucleotide/chemistry , Animals , Milk/microbiology , Microfluidic Analytical Techniques/instrumentation , Microspheres
4.
Anal Chem ; 96(4): 1454-1461, 2024 01 30.
Article in English | MEDLINE | ID: mdl-38224075

ABSTRACT

In this work, we present a simple and novel digital surface-enhanced Raman spectroscopy (SERS)-microfluidic chip designed for the rapid and accurate quantitative detection of microorganisms. The chip employs a high-density inverted pyramid microcavity (IPM) array to separate and isolate microbial samples. The presence or absence of target microorganisms is determined by scanning the IPM array using SERS and identifying the characteristic Raman bands. This approach allows for the "digitization" of the SERS response of each IPM, enabling quantification through the application of mathematical statistical techniques. Significantly, precise quantitative detection of yeast was achieved within a concentration range of 106-109 cells/mL, with the maximum relative standard deviation from the concentration calibrated by the cultivation method being 5.6%. This innovative approach efficiently addresses the issue of irregularities in SERS quantitative detection, which arises due to fluctuations in SERS intensity and poor reproducibility. We strongly believe that this digital SERS-microfluidic chip holds immense potential for diverse applications in the rapid detection of various microorganisms, including pathogenic bacteria and viruses.


Subject(s)
Microfluidics , Spectrum Analysis, Raman , Reproducibility of Results , Spectrum Analysis, Raman/methods , Oligonucleotide Array Sequence Analysis
5.
BMC Womens Health ; 23(1): 388, 2023 07 25.
Article in English | MEDLINE | ID: mdl-37491234

ABSTRACT

BACKGROUND: Increasing evidence has suggested that Corynebacterium kroppenstedtii is associated with some cases of granulomatous mastitis, mostly based on pathology or microbiology. We aimed to identify the clinical characteristics and treatment regimens for granulomatous mastitis with Corynebacterium kroppenstedtii infection. Understanding these clinical features is essential for patient care. METHODS: We retrospectively collected data on 201 patients who were pathologically diagnosed with granulomatous mastitis and had microbiological results of either Corynebacterium kroppenstedtii or no bacterial growth and recorded and analysed their demographics, clinical characteristics, and clinical outcomes. RESULTS: There were 107 patients in the CK group and 94 patients in the negative group. Sinus formation (x2 = 13.028, p = 0.000), time to complete remission at the first treatment period (Z = -3.027, p = 0.002), diameter of breast mass at first-time medical consultancy (Z = -2.539, p = 0.011) and recurrence (x2 = 4.953, p = 0.026) were statistically significant. Age (Z = -1.046, p = 0.295), laterality (x2 = 4.217, p = 0.121), time to presentation since the last delivery (x2 = 0.028, p = 0.868), BMI (Z = -0.947, p = 0.344), lactation time (Z = -1.378, p = 0.168), parity (x2 = 1.799, p = 0.180), gravida (Z = -0.144, p = 0.885), history of lactational mastitis or abscess (x2 = 0.115, p = 0.734), local trauma (x2 = 0.982, p = 0.322), hyperprolactinemia (x2 = 0.706, p = 0.401), erythema nodosum (x2 = 0.292, p = 0.589), and nipple discharge (x2 = 0.281, p = 0.596) did not demonstrate statistical significance. Regarding recurrence related to therapeutic strategy, except for surgery combined with immunosuppressants (x2 = 9.110, p = 0.003), which was statistically significant, none of the other treatment regimens reached statistical significance. The recurrence rate of patients in the CK group using rifampicin in their treatment course was 22.0% (x2 = 4.892, p = 0.027). CONCLUSIONS: Granulomatous mastitis accompanied by Corynebacterium kroppenstedtii more easily forms sinuses and has a higher recurrence rate. Both of the clinical characteristics may indicate that Corynebacterium kroppenstedtii plays an important role in the development and progression of granulomatous mastitis. Lipophilic antibiotics may be essential for granulomatous mastitis with Corynebacterium kroppenstedtii infection.


Subject(s)
Corynebacterium Infections , Granulomatous Mastitis , Female , Humans , Corynebacterium , Corynebacterium Infections/complications , Corynebacterium Infections/drug therapy , Corynebacterium Infections/diagnosis , Granulomatous Mastitis/complications , Granulomatous Mastitis/drug therapy , Retrospective Studies , Adult , Middle Aged
6.
Lab Chip ; 23(10): 2469-2476, 2023 05 16.
Article in English | MEDLINE | ID: mdl-37092607

ABSTRACT

In this paper, a multifunctional microfluidic chip integrated with a centrifugal separation zone, aqueous two-phase system (ATPS) mixing zone and enrichment detection zone was proposed and fabricated. An automatic and efficient separation and quantitative analysis method for vascular endothelial growth factor 165 (VEGF165) in whole blood samples was established with the designed microfluidic chip. A blood sample was divided into blood cells and plasma in the centrifugation zone. In the ATPS mixing zone, plasma was mixed with PEG/KH2PO4 aqueous two-phase solution containing Apt-Au NP nanoprobes. In the enrichment detection zone, the mixture was separated on CN140 modified with a ZnO NP-anti VEGF165 nanostructure. The VEGF165 captured by Apt-Au NPs was distributed in the PEG phase, concentrated at the front of CN140 and combined with anti-VEGF165 to form a sandwich structure. The sensitive detection of VEGF165 was achieved through fluorescence resonance energy transfer between rhodamine B and Au NPs on the nanoprobe. Under the optimized rotation program, capillary and centrifugal forces propelled the fluid in the whole process of pretreatment and detection. The detection linear range was between 1 pg mL-1 and 50 ng mL-1, the detection limit of VEGF165 in blood was 0.22 pg mL-1 and the enrichment efficiency was 983. It was illustrated that a convenient and reliable way for detection of tumor markers based on the multifunctional microfluidic chip was provided and it has a potential value for early screening and prognosis of clinical cancer.


Subject(s)
Microfluidics , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factor A/analysis , Biomarkers, Tumor , Water
7.
Lab Chip ; 23(8): 2113-2121, 2023 04 12.
Article in English | MEDLINE | ID: mdl-36946151

ABSTRACT

The quality of red blood cells (RBCs) in stored blood has a direct impact on the recovery of patients treated by blood transfusion, which directly reflects the quality of blood. The traditional means for blood quality evaluation involve the use of reagents and multi-step and time-consuming operations. Here, a low-cost, multi-classification, label-free and high-precision method is developed, which combines microfluidic technology and a deep learning algorithm together to recognize and classify RBCs based on morphology. The microfluidic channel is designed to effectively and controllably solve the problem of cell overlap, which has a severe negative impact on the identification of cells. The object detection model in the deep learning algorithm is optimized and used to recognize multiple RBCs simultaneously in the whole field of view, so as to classify them into six morphological subcategories and count the numbers in each subgroup. The mean average precision of the developed object detection model reaches 89.24%. The blood quality can be evaluated by calculating the morphology index (MI) according to the numbers of cells in subgroups. The validation of the method is verified by evaluating three blood samples stored for 7 days, 21 days and 42 days, which have MIs of 84.53%, 73.33% and 24.34%, respectively, indicating good agreement with the actual blood quality. This method has the merits of cell identification in a wide channel, no need for single cell alignment as the image cytometry does and it is not only applicable to the quality evaluation of RBCs, but can also be used for general cell identifications with different morphologies.


Subject(s)
Deep Learning , Humans , Algorithms , Blood Preservation/methods , Blood Transfusion , Erythrocytes , Lab-On-A-Chip Devices
8.
Biosensors (Basel) ; 13(3)2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36979564

ABSTRACT

There are various pathogenic bacteria in the surrounding living environment, which not only pose a great threat to human health but also bring huge losses to economic development. Conventional methods for bacteria detection are usually time-consuming, complicated and labor-intensive, and cannot meet the growing demands for on-site and rapid analyses. Sensitive, rapid and effective methods for pathogenic bacteria detection are necessary for environmental monitoring, food safety and infectious bacteria diagnosis. Recently, benefiting from its advantages of rapidity and high sensitivity, surface-enhanced Raman spectroscopy (SERS) has attracted significant attention in the field of bacteria detection and identification as well as drug susceptibility testing. Here, we comprehensively reviewed the latest advances in SERS technology in the field of bacteria analysis. Firstly, the mechanism of SERS detection and the fabrication of the SERS substrate were briefly introduced. Secondly, the label-free SERS applied for the identification of bacteria species was summarized in detail. Thirdly, various SERS tags for the high-sensitivity detection of bacteria were also discussed. Moreover, we emphasized the application prospects of microfluidic SERS chips in antimicrobial susceptibility testing (AST). In the end, we gave an outlook on the future development and trends of SERS in point-of-care diagnoses of bacterial infections.


Subject(s)
Bacterial Infections , Mycobacterium tuberculosis , Humans , Spectrum Analysis, Raman/methods , Microbial Sensitivity Tests , Food Safety
9.
Anal Bioanal Chem ; 414(26): 7683-7694, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36048191

ABSTRACT

Circulating tumor cells (CTCs), which have extremely low density in whole blood, are an important indicator of primary tumor metastasis. Isolation and enumeration of these cells are critical for clinical applications. Separation of CTCs from massive blood cells without labeling and addition of synthetic polymers is challenging. Herein, a novel well-defined co-flow microfluidic device is presented and used to separate CTCs in viscous blood by applying both inertial and viscoelastic forces. Diluted blood without any synthetic polymer and buffer solution were used as viscoelastic fluid and Newtonian fluid, respectively, and they were co-flowed in the designed chip to form a sheath flow. The co-flow system provides the function of particle pre-focusing and creates a tunable shear rate region at the interface to adjust the migration of particles or cells from the sample solution to the buffer solution. Successful separation of CTCs from viscous blood was demonstrated and enumeration was also conducted by image recognition after separation. The statistical results indicated that a recovery rate of cancer cells greater than 87% was obtained using the developed method, which proved that the direct separation of CTCs from diluted blood can be achieved without the addition of any synthetic polymer to prepare viscoelastic fluid. This method holds great promise for the separation of cells in viscous biological fluid without either complicated channel structures or the addition of synthetic polymers.


Subject(s)
Microfluidic Analytical Techniques , Neoplastic Cells, Circulating , Humans , Cell Separation , Neoplastic Cells, Circulating/pathology , Lab-On-A-Chip Devices , Viscosity , Polymers , Cell Line, Tumor
10.
Anal Chim Acta ; 1221: 340139, 2022 Aug 15.
Article in English | MEDLINE | ID: mdl-35934371

ABSTRACT

Developing sensitive and miniaturized biosensors for the detection of microRNAs (miRNAs) is highly desirable due to their association with early cancer diagnosis and prognosis. Here, a new microfluidic-based biosensor, combined with multifunctional nanosurface and DSN-assisted target recycle amplification strategy, is designed for the detection of miRNA-21. The design of nanosurface includes gold nanoparticles on porous anodic aluminum oxide (AAO) for surface enhanced Raman scattering (SERS) substrate, AuMBA@Ag core-shell nanoparticles for SERS nanotags and single-stranded DNA (ssDNA) in between for miRNA capture and nanotags immobilization. When the target miRNA is present near the nanosurface, it will be captured by ssDNA via hybridization reaction. Then, triggered by the DSN-assisted target recycle process, the freshly formed DNA/miRNA heteroduplexes are cleaved by DSN enzyme into DNA fragments and single-strand miRNA. The SERS nanotags are also dissociated from the nanosurface, leading to decrease of SERS signal. The cleaved target miRNA can be captured and SERS nanotags are released again in the next cycle, resulting in amplification of detection signal. To improve the accuracy of this biosensor, the functionalized AAO membrane is subdivided into two groups - AAO/Au array linked with encoded core-shell SERS nanotags acting as a reactor and primary detector and AAO/Au@Ag array serving as a collector and secondary detector for the dissociative SERS nanotags from the reactor. The decrease of SERS signal in primary detector and increase of signal in secondary detector ensures the accuracy and it is called dual-SERS detection strategy. The detection of miRNA-21 can be achieved with only 30 µL sample and 10 µL enzyme and a wide linear range of 10 fM∼10 nM is obtained. In addition, the microfluidic dual-SERS detection strategy can greatly reduce the possibility of false positive or false negative in single detection mode and it can be applied to the simultaneous detection of multiple miRNAs via integrating different probes.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , MicroRNAs , Biosensing Techniques/methods , DNA , Gold , Limit of Detection , MicroRNAs/genetics , Microfluidics , Spectrum Analysis, Raman/methods
11.
Dalton Trans ; 51(34): 12996-13002, 2022 Aug 30.
Article in English | MEDLINE | ID: mdl-35968727

ABSTRACT

Mercury(II) is one of the most toxic ions and has the lowest allowed concentration in water. Lowering the detection limits of Hg2+ based on fluorescence methods is challenging compared to the detection of other heavy metal ions. Co-precipitation of the CsPbBr3 precursor and mercury ions in aqueous solutions was developed for the ultra-trace level detection of Hg2+. It was found that the formed CsPbBr3 crystals with sizes in the range of nanometers to micrometers exhibited strong fluorescence in the solid state free of water, and the incorporation of Hg2+ in the crystals would cause fluorescence quenching. Therefore, the decrease in fluorescence intensity could be used to quantitatively detect Hg2+. A microwell array was designed by dispersing the sample solution with the perovskite probe and evaporating water for 3 min to form solid fluorescent crystals, leading to the incorporation of Hg2+ in the crystals. This evaporation-induced co-precipitation strategy successfully solved the problem of the instability of perovskite materials in water. The concentration of Hg2+ can be obtained according to the decrease in the fluorescence intensity, which is caused by the replacement of Pb2+ by Hg2+ in the crystals during the crystallization process. The CsPbBr3 crystallites can be used to detect ultra-trace levels of Hg2+ simply and quickly, with a linear range of 5-100 nM and limit of detection (LOD) as low as 0.1 nM. More importantly, no organic molecules are required to prepare crystals since the micron-sized crystals have obvious fluorescence. This method demonstrates great promise in detecting low concentrations of Hg2+ in aqueous solutions.

12.
ACS Sens ; 7(4): 1019-1026, 2022 04 22.
Article in English | MEDLINE | ID: mdl-35362948

ABSTRACT

For the rapid and sensitive detection of vascular endothelial growth factor 165 (VEGF165) in clinical blood samples, a microfluidic sensing chip that integrates a centrifugal separation pretreatment unit and a composite nanosensing film was proposed in this paper. An efficient sensing strategy and method was established. The blood sample was first separated and extracted by centrifugal force on the centrifugal microfluidic chip within 5 min after injection. The separated plasma can be automatically transferred through the designed microchannels to the detection area integrated electrodes for subsequent differential pulse voltammetric detection. The Au NPs/MCH/Apt2 sensing film was constructed on the surface of the Au working electrode. A sandwich sensing strategy based on "double aptamers" and "nanoprobe" for VEGF165 detection was established, by which the synthetic Apt1/PThi/Au NP nanoprobe was applied to capture VEGF165 in plasma and bind to the sensing film. By this method, the detection limit of VEGF165 in whole blood was 0.67 pg/mL and the linear range was between 1 pg and 10 ng, which met the needs of clinical VEGF165 detection. It was illustrated that the proposed methodology based on the centrifugal microfluidic chip had potential application prospects in the development of the point-of-care testing fields.


Subject(s)
Microfluidics , Vascular Endothelial Growth Factor A , Electrodes , Oligonucleotides
13.
Biosens Bioelectron ; 203: 114044, 2022 May 01.
Article in English | MEDLINE | ID: mdl-35123316

ABSTRACT

A biosensor integrated with mannose nano-surface was developed for the identification and adhesive strength evaluation of bacteria. Different bacteria were studied on the designed surface by both electrochemical impedance spectroscopy (EIS) and surface enhanced Raman spectroscopy (SERS). S. typhimurium and E. coli JM109 (type 1 pili) were found to be captured by the mannose nano-surface. SERS spectra were used to identify the species of captured bacteria by combing with partial least squares discriminant analysis (PLS-DA). Meanwhile, binding affinities of the two captured bacteria to mannose nano-surface were obtained by EIS measurements and Frumkin isotherm model analysis, which were 6.859 × 1023 M-1 and 2.054 × 1017 M-1 respectively. A higher binding affinity indicates a stronger adhesive strength. Hence the results show the S. typhimurium has a stronger adhesive strength to mannose. Normalized impedance change (NIC) was proved to have a positive relevant relationship with binding affinities, which could be used as an indicator for the adhesive strength of bacteria. It was demonstrated that 100% accuracy of bacteria species discrimination and good consistency of NIC and adhesive strength for blind samples. The developed biosensor can provide both qualitative and quantitative information of selective recognition between bacteria and mannose.


Subject(s)
Biosensing Techniques , Adhesives , Escherichia coli , Mannose , Spectrum Analysis, Raman/methods
14.
Biosens Bioelectron ; 204: 114057, 2022 May 15.
Article in English | MEDLINE | ID: mdl-35168025

ABSTRACT

The efficient detection of cancer markers has faced many challenges, such as severe interference, complicated and time-consuming operation, low sensitivity and so on. In this paper, a microfluidic chip integrated with electrodes for dielectrophoretic (DEP) separation, microchannels for electrochemical nanoprobes binding and differential pulse voltammetry (DPV) detection was proposed for the sensitive and rapid detection of prostate specific antigen (PSA) in whole blood. The functional units, which could realize cell separation, PSA derivatization (binding of electrochemical nanoprobes), capture and detection, were integrated on the microfluidic chip. The well-designed V-shaped interdigital electrode arrays provided DEP separation for blood cells with efficiency as high as 98%. Particularly, DEP effect significantly improved the sensitivity of PSA detection and reduced the detection limit by two orders of magnitude. In order to achieve sensitive detection of PSA, binding of electrochemical nanoprobes and then DPV detection was selected and integrated following the DEP separation. A sandwich structure based on electrochemical nanoprobes and dual-aptamers for on-chip DPV detection was proposed, which included self-synthesized electrochemical nanoprobes bovine serum albumin/detection aptamer 2/polythionine@gold nanoparticles (BSA/Apt2/PThi@Au NPs), target PSA, and sensing interface 6-mercaptohexanol/capture aptamer 1/gold nanoparticles on gold electrode (MCH/Apt1/Au NPs/Au). The method of quantitative detection of PSA in whole blood was then established. The excellent performance of the microfluidic chip allowed the determination of PSA in whole blood in the range of 1 pg/mL ∼10 ng/mL with an ultralow limit of detection of 0.25 pg/mL, which was better than the results obtained by conventional methods.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Metal Nanoparticles , Prostate-Specific Antigen/blood , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Electrochemical Techniques/methods , Gold/chemistry , Humans , Limit of Detection , Male , Metal Nanoparticles/chemistry , Microfluidics/instrumentation , Prostatic Neoplasms/diagnosis
15.
Small ; 17(43): e2103312, 2021 10.
Article in English | MEDLINE | ID: mdl-34585504

ABSTRACT

The sensitivity and linearity are critical parameters that can preserve the high pressure-resolution across a wide range and simplify the signal processing process of flexible tactile sensors. Although extensive micro-structured dielectrics have been explored to improve the sensitivity of capacitive sensors, the attenuation of sensitivity with increasing pressure is yet to be fully resolved. Herein, a novel dielectric layer based on the gradient micro-dome architecture (GDA) is presented to simultaneously realize the high sensitivity and ultrabroad linearity range of capacitive sensors. The gradient micro-dome pixels with rationally collocated amount and height can effectively regulate the contact area and hence enable the linear variation in effective dielectric constant of the GDA dielectric layer under varying pressures. With systematical optimization, the sensor exhibits the high sensitivity of 0.065 kPa-1 in an ultrabroad linearity range up to 1700 kPa, which is first reported. Based on the excellent sensitivity and linearity, the high pressure-resolution can be preserved across the full scale of pressure spectrum. Therefore, potential applications such as all-round physiological signal detection in diverse scenarios, control instruction transmission with combinatorial force inputs, and convenient Morse code communication with non-overlapping capacitance signals are successfully demonstrated through a single sensor device.


Subject(s)
Wearable Electronic Devices , Electric Capacitance , Mechanical Phenomena , Pressure , Touch
16.
Nanotechnology ; 32(39)2021 Jul 09.
Article in English | MEDLINE | ID: mdl-34161934

ABSTRACT

Serum creatinine is a key biomarker for the diagnosis and monitoring of kidney disease. Rapid and sensitive creatinine detection is thus important. Here, we propose a high-performance nano-Ag/Au@Au film composite SERS substrate for the rapid detection of creatinine in human serum. Au nanoparticles (AuNPs) and Ag nanoparticles (AgNPs) with uniform particle size were synthesized by a chemical reduction method, and the nano-Ag/Au@Au film composite SERS substrate was successfully prepared via a consecutive layer-on-layer deposition using an optimized liquid-liquid interface self-assembly method. The finite element simulation analysis showed that due to the multi-dimensional plasmonic coupling effect formed between the AuNPs, AgNPs, and the Au film, the intensity of the local electromagnetic field was greatly improved, and a very high enhancement factor (EF) was obtained. Experimental results showed that the limit of detection (LOD) of this composite SERS substrate for rhodamine 6G (R6G) molecules was as low as 1 × 10-13M, and the Raman EF was 15.7 and 2.9 times that of the AuNP and AgNP monolayer substrates respectively. The results of different batch tests and SERS mapping showed that the relative standard deviations of the Raman intensity of R6G at 612 cm-1were 12.5% and 11.7%, respectively. Finally, we used the SERS substrate for the label-free detection of human serum creatinine. The results showed that the LOD of this SERS substrate for serum creatinine was 5 × 10-6M with a linear correlation coefficient of 0.96. In conclusion, the SERS substrate has high sensitivity, good uniformity, simple preparation, and has important developmental potential for the rapid detection and application of disease biomarkers.

17.
Breastfeed Med ; 16(9): 759-764, 2021 09.
Article in English | MEDLINE | ID: mdl-33872053

ABSTRACT

Background: We have already known that idiopathic granulomatous mastitis (IGM) is a rare benign chronic inflammatory disorder that can clinically mimic breast carcinoma, especially affects parous women of childbearing age, but there is little literature to report about pregnancy associated granulomatous mastitis (PAGM). The aim of our study is to report and describe the clinical signs, managements, clinical course, and clinical outcomes after treatment of PAGM in our hospital. Methods: We retrospectively analyzed 15 pregnant patients who were diagnosed as PAGM in our hospital collected from December 2018 to December 2020 by reviewing medical records and questionnaire survey, including the patients' characteristics, clinical presentations, microbiological workups, tissue pathology, treatment modalities, outcomes, and follow-up data. Results: The mean age of these patients at diagnosis was 30.5 (range 24-35) years. All patients had one birth before, and had at least two gravida times, 6 of them (40%) had three gravida times, and only one of them had four gravida times at diagnosis. The mean weeks of gestational age were 23.7 (range 4-37) weeks. Two patients' BMI were greater than 30, which were considered obese. The mean time to presentation since last delivery was 38.4 (range 19-78) months. All patients had a history of breastfeeding; the average breastfeeding time was 12.97 months. Just 2 of them were diagnosed with lactational mastitis before. One patient smoked before, 1 patient had oral contraceptive pills before, 4 patients had breast trauma recently, 5 patients had positive bacterial culture of pyogenic fluids, 3 patients had nipple retraction, 6 patients had abnormal humoral immunity, shown as elevated C3 or C4, and 2 patients had elevated serum prolactin. All patients presented as a breast mass with pain; two of them had erythema nodosum and oligoarthritis. Nearly all patients had unilateral lesion. The mean follow-up was 11 (range 1-24) months. Thirteen patients gave birth to a healthy baby, and all babies had a healthy growth and development. Almost all patients chose observation during pregnancy. Nine patients demonstrated complete remission, five of them underwent surgery after steroids and/or antibiotics, one patient had observation alone, two chose postpartum steroids alone, and the last one chose postpartum antibiotics alone. The average time to complete remission was 11.2 (range 7-18) months. Conclusions: In general, PAGM is a much rare disorder which has onset during pregnancy, and mainly happens in the second trimester and the third trimester. PAGM patients were all parous women and generally within 5 years of their last pregnancy, also with uncertain etiology and pathogenesis. Observational therapy during pregnancy for PAGM is reliable and feasible.


Subject(s)
Breast Neoplasms , Granulomatous Mastitis , Mastitis , Adult , Breast , Breast Feeding , Female , Granulomatous Mastitis/diagnosis , Granulomatous Mastitis/therapy , Humans , Infant , Pregnancy , Retrospective Studies , Young Adult
18.
ACS Appl Mater Interfaces ; 13(1): 1754-1765, 2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33393309

ABSTRACT

Droplet manipulations are critical for applications ranging from biochemical analysis, medical diagnosis to environmental controls. Even though magnetic actuation has exhibited great potential, the capability of high-speed, precise manipulation, and mixing improvement covering a broad droplet volume has not yet been realized. Herein, we demonstrated that the magnetic actuation could be conveniently achieved via decorating the magnetically responsive film with microcilia. Under magnetic field, the film can quickly response with localized deformation, along with the microcilia to realize the surface superhydrophobicity for droplet manipulation with velocity up to ∼173 mm/s covering a broad volume of 2-100 µL. The robust system further allows us to realize rapid and complete droplet mixing within ∼1.6 s. In addition, the microcilia decorated surface can preserve the robust superhydrophobicity after various stability tests, for example, normal pressing, chemical corrosion, and mechanical abrasion, exhibiting the possibility toward the long-term and real applications. With the multifunctional demonstrations such as obvious mixing improvement, parallel manipulation, and serial dilution, we believe that the methodology can open up a magnetic field-based avenue for future applications in digital microfluidics, and biochemical assays, etc.

19.
J Mater Chem B ; 8(36): 8315-8322, 2020 09 23.
Article in English | MEDLINE | ID: mdl-32785401

ABSTRACT

Electronic skins (e-skins) with monitoring capabilities have attracted extensive attention and are being widely employed in wearable devices for medical diagnosis. In particular, e-skins based on strain sensors have been reported extensively due to their simple structure and efficient performance in collecting human physiological information. Flexible sensors with high sensitivity, simplified fabrication, and low-cost are highly desired for human signal monitoring; this work provides a novel strain-sensing e-skin with micro-structures, which is simply made of modified polydimethylsiloxane (PDMS) and silver nanowires (AgNWs). The fabricated e-skin has great sensitivity towards strain changes, and its mechanical properties and sensitivity could be regulated by varying the micro-structures. Furthermore, the e-skin demonstrated significant capacity for monitoring human body movements, temperature changes, and spatial resolution, highlighting its great potential in personalized medicine.


Subject(s)
Dimethylpolysiloxanes/chemistry , Monitoring, Physiologic/methods , Wearable Electronic Devices , Humans , Monitoring, Physiologic/instrumentation , Movement , Nanowires/chemistry , Silver/chemistry , Temperature
20.
Biomater Sci ; 8(17): 4852-4860, 2020 Sep 07.
Article in English | MEDLINE | ID: mdl-32734981

ABSTRACT

The formation of bacterial biofilms is a key factor in the emergence of chronic infections due to the strong resistance of biofilms to conventional antibiotics. There is an urgent need to develop an effective strategy to control the formation of biofilms. In this study, a nanocomposite of tannic acid and silver (Tannin-AgNPs) was designed and successfully prepared based on the quorum sensing (QS) inhibitory activity of tannic acid and the anti-bacterial activity of silver. The dynamic light scattering and SEM observations indicated that the obtained Tannin-AgNPs were spherical with a mean particle size of 42.37 nm. Tannic acid was successfully modified on the surface of silver nanoparticles and characterized via Fourier transform infrared (FTIR) spectroscopy. The prepared Tannin-AgNPs demonstrated a more effective anti-bacterial and anti-biofilm activity against E. coli than the unmodified AgNPs or tannic acid. In addition, the Tannin-AgNPs can modulate the formation process of E. coli biofilms, shorten the growth period of biofilms and extend the dispersion period of biofilms. Tannin-AgNPs also showed the function of decreasing the production of the QS signal molecule. The proposed strategy of constructing a nanocomposite using AgNPs and natural components with QS inhibitory activity is effective and promising for inhibiting the formation of biofilms.


Subject(s)
Metal Nanoparticles , Silver , Anti-Bacterial Agents/pharmacology , Biofilms , Escherichia coli , Microbial Sensitivity Tests , Silver/pharmacology , Tannins
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