scholarly journals Colorimetric Nanoplasmonics to Spot Hyperglycemia From Saliva

2020 ◽  
Vol 8 ◽  
Author(s):  
Paolo Donati ◽  
Tania Pomili ◽  
Luca Boselli ◽  
Pier P. Pompa
Keyword(s):  
Large Scale ◽  
Point Of Care ◽  
High Sensitivity ◽  
Diabetic Patients ◽  
Visual Response ◽  
Colorimetric Sensing ◽  
Chronic Patients ◽  
Self Monitoring ◽  
Sensing Platform ◽  
Signal Color

Early diagnostics and point-of-care (POC) devices can save people’s lives or drastically improve their quality. In particular, millions of diabetic patients worldwide benefit from POC devices for frequent self-monitoring of blood glucose. Yet, this still involves invasive sampling processes, which are quite discomforting for frequent measurements, or implantable devices dedicated to selected chronic patients, thus precluding large-scale monitoring of the globally increasing diabetic disorders. Here, we report a non-invasive colorimetric sensing platform to identify hyperglycemia from saliva. We designed plasmonic multibranched gold nanostructures, able to rapidly change their shape and color (naked-eye detection) in the presence of hyperglycemic conditions. This “reshaping approach” provides a fast visual response and high sensitivity, overcoming common detection issues related to signal (color intensity) losses and bio-matrix interferences. Notably, optimal performances of the assay were achieved in real biological samples, where the biomolecular environment was found to play a key role. Finally, we developed a dipstick prototype as a rapid home-testing kit.

scholarly journals Colorimetric and Fluorescent Dual-Modality Sensing Platform Based on Fluorescent Nanozyme

2021 ◽  
Vol 9 ◽  
Author(s):  
Yejian Wan ◽  
Jingwen Zhao ◽  
Xiaochun Deng ◽  
Jie Chen ◽  
Fengna Xi ◽  
...  
Keyword(s):  
Large Scale ◽  
Hydrothermal Process ◽  
Single Layer ◽  
High Sensitivity ◽  
Single Layer Graphene ◽  
Peroxidase Mimic ◽  
Uniform Size ◽  
Dual Modality ◽  
Sensing Platform ◽  
N Doping

Compared with natural enzymes, nanozymes based on carbonaceous nanomaterials are advantages due to high stability, good biocompatibility, and the possibility of multifunctionalities through materials engineering at an atomic level. Herein, we present a sensing platform using a nitrogen-doped graphene quantum dot (NGQD) as a highly efficient fluorescent peroxidase mimic, which enables a colorimetric/fluorescent dual-modality platform for detection of hydrogen peroxide (H2O2) and biomolecules (ascorbic acid-AA, acid phosphatase-ACP) with high sensitivity. NGQD is synthesized using a simple hydrothermal process, which has advantages of high production yield and potential for large-scale preparation. NGQD with uniform size (3.0 ± 0.6 nm) and a single-layer graphene structure exhibits bright and stable fluorescence. N-doping and ultrasmall size endow NGQD with high peroxidase-mimicking activity with an obviously reduced Michaelis–Menten constant (Km) in comparison with natural horseradish peroxidase. Taking advantages of both high nanozyme activity and unique fluorescence property of NGQD, a colorimetric and fluorescent dual-modality platform capable of detecting H2O2 and biomolecules (AA, ACP) with high sensitivity is developed as the proof-of-concept demonstration. Furthermore, the mechanisms underlying the nanozyme activity and biosensing are investigated.

Low-cost and high sensitivity glucose sandwich detection using a plasmonic nanodisk metasurface

Nanoscale ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 10809-10815 ◽  
Author(s):  
Zhongwen Long ◽  
Yuzhang Liang ◽  
Lei Feng ◽  
Hui Zhang ◽  
Mingze Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
High Sensitivity ◽  
Glucose Detection ◽  
Sensing Platform ◽  
Highly Sensitive

A low-cost, large scale plasmonic metasurface sensing platform shows enormous potential for highly sensitive and selective SERS-based glucose detection.

scholarly journals Nanosensors for Visual Detection of Glucose in Biofluids: Are We Ready for Instrument-Free Home-Testing?

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1978
Author(s):  
Luca Boselli ◽  
Tania Pomili ◽  
Paolo Donati ◽  
Pier P. Pompa
Keyword(s):  
Large Scale ◽  
Life Quality ◽  
Cost Effective ◽  
Solid Base ◽  
Chronic Patients ◽  
Self Monitoring ◽  
Diagnostic Strategies ◽  
Non Invasive ◽  
Home Testing ◽  
Main Instrument

Making frequent large-scale screenings for several diseases economically affordable would represent a real breakthrough in healthcare. One of the most promising routes to pursue such an objective is developing rapid, non-invasive, and cost-effective home-testing devices. As a first step toward a diagnostic revolution, glycemia self-monitoring represents a solid base to start exploring new diagnostic strategies. Glucose self-monitoring is improving people’s life quality in recent years; however, current approaches still present vast room for improvement. In most cases, they still involve invasive sampling processes (i.e., finger-prick), quite discomforting for frequent measurements, or implantable devices which are costly and commonly dedicated to selected chronic patients, thus precluding large-scale monitoring. Thanks to their unique physicochemical properties, nanoparticles hold great promises for the development of rapid colorimetric devices. Here, we overview and analyze the main instrument-free nanosensing strategies reported so far for glucose detection, highlighting their advantages/disadvantages in view of their implementation as cost-effective rapid home-testing devices, including the potential use of alternative non-invasive biofluids as samples sources.

A smartphone readable colorimetric sensing platform for rapid multiple protein detection

The Analyst ◽  
2017 ◽  
Vol 142 (17) ◽  
pp. 3177-3182 ◽  
Author(s):  
Feiyang Wang ◽  
Yuexiang Lu ◽  
Jiacheng Yang ◽  
Ying Chen ◽  
Wenjie Jing ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Sensor Array ◽  
Point Of Care ◽  
Protein Detection ◽  
Colorimetric Sensor ◽  
Colorimetric Sensing ◽  
Colorimetric Sensor Array ◽  
Sensing Platform ◽  
Multiple Protein

We have developed a very simple colorimetric sensor array by using only unmodified gold nanoparticles and NaCl salt for discrimination of multiple proteins. The inexpensive and convenient sensor array and the ubiquitous smartphone are coupled to achieve an immediate point-of-care diagnosis without additional devices.

The comparison of two glucose measurement systems: POCT devices versus central laboratory

2018 ◽  
Vol 43 (5) ◽  
pp. 510-519
Author(s):  
Nurcan Kilic Baygutalp ◽  
Ebubekir Bakan ◽  
Zafer Bayraktutan ◽  
Fatma Zuhal Umudum
Keyword(s):  
Health Care Professionals ◽  
Clinical Laboratory ◽  
Point Of Care ◽  
Laboratory Method ◽  
Test Reliability ◽  
Glucose Measurement ◽  
Diabetic Patients ◽  
Self Monitoring ◽  
Therapeutic Decisions ◽  
Glucose Meter

Abstract Background: Glucose meters are used for two purposes: point-of-care testing and the self-monitoring of glucose, both of which are very important in the management of diabetes, hypoglycemia, or hyperglycemia and in therapeutic decisions. Objective: The aim of this study was to determine the test reliability of glucose meters and to compare their results with those of the clinical laboratory method. Material and methods: Evaluation was made of five different types of glucose meters which are generally used for hospitalized patients. Capillary and venous specimens were obtained concurrently from each patient. The former were analyzed in the glucose meters, and the latter in the laboratory analyzer. Results: Of 1837 glucose meters read-outs, 1748 capillary and venous comparisons were evaluated. The majority of the glucose meter measurements were within acceptable limits. The error percentage distribution of glucose meters indicated that the accuracy of glucose meters is higher in the prediabetic/diabetic measurement range than at normo-/hypoglycemic levels. Conclusion: In general, the glucose meters and laboratory method were observed to be compatible. However, health care professionals and self-monitoring diabetic patients should be aware of the evaluation of glucose meter results, and should cross-check, as frequently as possible, with laboratory values.

scholarly journals Accessible LAMP-Enabled Rapid Test (ALERT) for Detecting SARS-CoV-2

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 742
Author(s):  
Ali Bektaş ◽  
Michael F. Covington ◽  
Guy Aidelberg ◽  
Anibal Arce ◽  
Tamara Matute ◽  
...  
Keyword(s):  
Large Scale ◽  
Point Of Care ◽  
False Negative ◽  
Rapid Test ◽  
High Sensitivity ◽  
Surface Proteins ◽  
Influenza B ◽  
True Negative ◽  
Free Concentration ◽  
Primer Sets

The coronavirus disease 2019 (COVID-19) pandemic has highlighted bottlenecks in large-scale, frequent testing of populations for infections. Polymerase chain reaction (PCR)-based diagnostic tests are expensive, reliant on centralized labs, can take days to deliver results, and are prone to backlogs and supply shortages. Antigen tests that bind and detect the surface proteins of a virus are rapid and scalable but suffer from high false negative rates. To address this problem, an inexpensive, simple, and robust 60-minute do-it-yourself (DIY) workflow to detect viral RNA from nasal swabs or saliva with high sensitivity (0.1 to 2 viral particles/μL) and specificity (>97% true negative rate) utilizing reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed. ALERT (Accessible LAMP-Enabled Rapid Test) incorporates the following features: (1) increased shelf-life and ambient temperature storage, compared to liquid reaction mixes, by using wax layers to isolate enzymes from other reagents; (2) improved specificity compared to other LAMP end-point reporting methods, by using sequence-specific QUASR (quenching of unincorporated amplification signal reporters); (3) increased sensitivity, compared to methods without purification through use of a magnetic wand to enable pipette-free concentration of sample RNA and cell debris removal; (4) quality control with a nasopharyngeal-specific mRNA target; and (5) co-detection of other respiratory viruses, such as influenza B, by multiplexing QUASR-modified RT-LAMP primer sets. The flexible nature of the ALERT workflow allows easy, at-home and point-of-care testing for individuals and higher-throughput processing for labs and hospitals. With minimal effort, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific primer sets can be swapped out for other targets to repurpose ALERT to detect other viruses, microorganisms, or nucleic acid-based markers.

scholarly journals Colorimetric detection of individual biothiols by tailor made reactions with silver nanoprisms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pei Li ◽  
Sang Mo Lee ◽  
Hyo Yong Kim ◽  
Soohyun Kim ◽  
Steve Park ◽  
...  
Keyword(s):  
Human Serum ◽  
Colorimetric Detection ◽  
Chloride Ion ◽  
High Sensitivity ◽  
Cost Effective ◽  
Colorimetric Sensing ◽  
Practical Applications ◽  
Silver Nanoprisms ◽  
Sensing Platform ◽  
Sensitivity And Selectivity

AbstractWe herein described a rapid, sensitive, and selective colorimetric sensing platform for biothiols in human serum, which relies on the dual functions of biothiols as anti-etching and aggregating agent for silver nanoprisms (AgNPRs). In principle, the target biothiols that bind to the surface of AgNPRs through Ag–S covalent interactions protect the AgNPRs from being etched by chloride ion (Cl−) in human serum, thus exhibiting the blue/purple color that is indicative of AgNPRs. On the other hand, the color of AgNPRs turned to yellow in the absence of biothiols or the presence of non-sulfur-containing amino acids, indicating the formation of small silver nanoparticles (AgNPs). Importantly, we found that individual biothiols (Hcy, Cys, and GSH) exert not only the anti-etching effect, but also the aggregating effect on AgNPRs, which can be modulated by simply tuning the pH conditions, and this consequently allows for the discriminative detection of each biothiol. Based on this simple and cost-effective strategy, we successfully determined the Hcy, Cys, and GSH in human serum with high sensitivity and selectivity within 10 min, demonstrating the diagnostic capability and potential in practical applications.

scholarly journals A novel colorimetric sensing platform for the detection of S. aureus with high sensitivity and specificity

RSC Advances ◽  
2019 ◽  
Vol 9 (58) ◽  
pp. 33589-33595 ◽  
Author(s):  
Yun Zhang ◽  
Shuyou Shi ◽  
Jiajia Xing ◽  
Wenqing Tan ◽  
Chenguang Zhang ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Protein A ◽  
High Sensitivity ◽  
Selective Detection ◽  
Colorimetric Sensing ◽  
Sensing Platform ◽  
P Utilization

Utilization of dog IgG and chicken anti-protein A IgY as an antibody pair for sensitive and selective detection of S. aureus.

scholarly journals Nicotinamide-functionalized carbon quantum dot as new sensing platform for portable quantification of vitamin B12 in fluorescence, UV-Vis and smartphone triple mode

2021 ◽  
Author(s):  
Sahar Dadkhah ◽  
Ali Mehdinia ◽  
Ali Jabbari ◽  
Ahmad Manbohi
Keyword(s):  
Quantum Dot ◽  
Vitamin B12 ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Colorimetric Sensing ◽  
Practical Applications ◽  
Carbon Quantum Dot ◽  
Sensing Platform ◽  
Triple Mode

Abstract Development of an efficient, portable and simple nanosensor-based systems with reliable analytical performance for on-site monitoring of vitamin B12 (VB12) are still major problems and a challenging work for quality control of manufacturers. Herein, a new fluorescence, UV-Vis and smartphone triple mode nanosensors were designed for the simultaneous detection of VB12 with high sensitivity and accuracy. A novel nanosensor was synthesized through nicotinamide-functionalizing on carbon quantum dot (NA-CQDs) by an one-step microwave-assisted method with green approaches. The NA-CQDs as new nanosensor showed excellent fluorescence properties and wide linear ranges from 0.1–60 µM with the detection limits of 31.7 nM. Moreover, color changes of NA-CQDs induced by the VB12 could also be detected by UV-Vis spectrophotometer and inhouse-developed application installed on smartphone as a signal reader, simultanusly. The Red, Green and Blue (RGB) intensities of the colorimetric images of NA-CQDs/VB12 system which taken by smartphone's camera converted into quantitative values by the introduced application. A smartphone-integrated with NA-CQDs as colorimetric sensing platform displays good linear ranges (4.16 to 66.6 µM) for on-site determination of VB12 with detection limit of 1.40 µM. The method was successfully applied in the determination of VB12 in complex pharmaceutical supplement formulations without any sample pre-treatment and matrix interfering effects. The recovery results (96.52–105.10%) which are in agreement with the reference methods, demonstrating the capability of the smartphone-assisted colorimetric sensing platform in many on-site practical applications of quality controls.

scholarly journals A Reverse Transcription Recombinase-Aided Amplification Method for Rapid and Point-of-Care Detection of SARS-CoV-2, including Variants

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1875
Author(s):  
Fengyun Li ◽  
Ping He ◽  
Dongyan Xiong ◽  
Yakun Lou ◽  
Qiaosheng Pu ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Large Scale ◽  
Point Of Care ◽  
High Sensitivity ◽  
High Agreement ◽  
Amplification Method ◽  
In Situ Methods ◽  
Diagnostic Applications ◽  
Point Of Care Detection

The worldwide pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and its emergence of variants needs rapid and point-of-care testing methods for a broad diagnosis. The regular RT-qPCR is time-consuming and limited in central laboratories, so a broad and large-scale screening requirement calls for rapid and in situ methods. In this regard, a reverse transcription recombinase-aided amplification (RT-RAA) is proposed here for the rapid and point-of-care detection of SARS-CoV-2. A set of highly conserved primers and probes targeting more than 98% of SARS-CoV-2 strains, including currently circulating variants (four variants of concerns (VOCs) and three variants of interest (VOIs)), was used in this study. With the preferred primers, the RT-RAA assay showed a 100% specificity to SARS-CoV-2 from eight other respiratory RNA viruses. Moreover, the assay here is of a high sensitivity and 0.48 copies/μL can be detected within 25 min at a constant temperature (42 °C), which can be realized on portable equipment. Furthermore, the RT-RAA assay demonstrated its high agreement for the detection of SARS-CoV-2 in clinical specimens compared with RT-qPCR. The rapid, simple and point-of-care RT-RAA method is expected to be an appealing detection tool to detect SARS-CoV-2, including variants, in clinical diagnostic applications.

Sign in / Sign up

Export Citation Format

Share Document