Nanostructured Organic/Hybrid Materials and Components in Miniaturized Optical and Chemical Sensors

In the last decade, biochemical sensors have brought a disruptive breakthrough in analytical chemistry and microbiology due the advent of technologically advanced systems conceived to respond to specific applications. From the design of a multitude of different detection modalities, several classes of sensor have been developed over the years. However, to date they have been hardly used in point-of-care or in-field applications, where cost and portability are of primary concern. In the present review we report on the use of nanostructured organic and hybrid compounds in optoelectronic, electrochemical and plasmonic components as constituting elements of miniaturized and easy-to-integrate biochemical sensors. We show how the targeted design, synthesis and nanostructuring of organic and hybrid materials have enabled enormous progress not only in terms of modulation and optimization of the sensor capabilities and performance when used as active materials, but also in the architecture of the detection schemes when used as structural/packing components. With a particular focus on optoelectronic, chemical and plasmonic components for sensing, we highlight that the new concept of having highly-integrated architectures through a system-engineering approach may enable the full expression of the potential of the sensing systems in real-setting applications in terms of fast-response, high sensitivity and multiplexity at low-cost and ease of portability.

Download Full-text

Integrating high-performing electrochemical transducers in lateral flow assay

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-021-03301-y ◽

2021 ◽

Author(s):

Antonia Perju ◽

Nongnoot Wongkaew

Keyword(s):

High Performance ◽

Point Of Care ◽

Low Cost ◽

High Sensitivity ◽

Lateral Flow ◽

Analytical Performance ◽

Label Free ◽

High Performing ◽

Lateral Flow Assays ◽

Electrochemical Transducers

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.

Download Full-text

Electroanalytical Biosensors for Circulating Tumor DNA Detection—A Brief Review

10.20944/preprints202111.0357.v1 ◽

2021 ◽

Author(s):

Zhijia Peng ◽

Xiaogang Lin ◽

Weiqi Nian ◽

Xiaodong Zheng ◽

Jayne Wu

Keyword(s):

Real Time ◽

Point Of Care ◽

Low Cost ◽

High Sensitivity ◽

High Specificity ◽

Circulating Tumor Dna ◽

Minimal Invasive ◽

Diagnosis And Treatment ◽

Detection Technology ◽

Tumor Dna

Early diagnosis and treatment have always been highly desired in the fight against cancer, and detection of circulating tumor DNA (ctDNA) has recently been touted as highly promising for early cancer screening. Consequently, the detection of ctDNA in liquid biopsy gains much attention in the field of tumor diagnosis and treatment, which has also attracted research interest from the industry. However, traditional gene detection technology is difficult to achieve low cost, real-time and portable measurement of ctDNA. Electroanalytical biosensors have many unique advantages such as high sensitivity, high specificity, low cost and good portability. Therefore, this review aims to discuss the latest development of biosensors for minimal-invasive, rapid, and real-time ctDNA detection. Various ctDNA sensors are reviewed with respect to their choices of receptor probes, detection strategies and figures of merit. Aiming at the portable, real-time and non-destructive characteristics of biosensors, we analyze their development in the Internet of Things, point-of-care testing, big data and big health.

Download Full-text

Simulation and performance analysis of Multiple PCS sensors system

Electronics ETF ◽

10.7251/els1620085w ◽

2017 ◽

Vol 20 (2) ◽

pp. 85

Author(s):

Pawan Whig ◽

Syed Naseem Ahmad ◽

Surinder Kumar

Keyword(s):

Low Cost ◽

Reference Electrode ◽

Oxygen Demand ◽

High Sensitivity ◽

Readout Circuit ◽

Active Components ◽

Multiple Sensors ◽

Quality Of Water ◽

Voltage Signal ◽

And Performance

In this paper, a novel circuit is presented which overcome a serious limitation found in case of multiple sensors system. In this novel system design only one reference electrode and few active components used that makes the implementation of a low-cost system for the supervision of water quality. Photo Catalytic Sensor (PCS) estimates the parameter BOD (Biological Oxygen Demand) which is generally used to estimate quality of water. The system proposed in this paper involves a balanced bridge approach using few electronic components that provides a correlation in the input-output signals of low-cost sensors. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans conductance gain. The trans-conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O2 in the solution.

Download Full-text

Easy-to-Fabricate K2Pd(SO3)2-Dyed Polyester Fabric with Highly Selective and Fast Response to Carbon Monoxide

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19418 ◽

2021 ◽

Vol 21 (8) ◽

pp. 4400-4405

Author(s):

Junyeop Lee ◽

Nam Gon Do ◽

Dong Hyuk Jeong ◽

Sae-Wan Kim ◽

Maeum Han ◽

...

Keyword(s):

Carbon Monoxide ◽

Color Change ◽

High Sensitivity ◽

Cost Effective ◽

Fast Response ◽

Polyester Fabric ◽

High Porosity ◽

Sensing Material ◽

Sensitivity And Selectivity ◽

And Performance

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

Download Full-text

Gas Sensing Properties of TiO2 and SnO2 Nanopowders Obtained through Gel Combustion

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.1828 ◽

2006 ◽

Vol 45 ◽

pp. 1828-1833

Author(s):

Fabio A. Deorsola ◽

P. Mossino ◽

Ignazio Amato ◽

Bruno DeBenedetti ◽

A. Bonavita ◽

...

Keyword(s):

Response Time ◽

Metal Oxides ◽

Gas Sensing ◽

Low Cost ◽

High Sensitivity ◽

Fast Response ◽

High Specific Surface Area ◽

Research Field ◽

Wide Range ◽

Gel Combustion

Nanostructured semiconductor metal oxides have played a central role in the gas sensing research field, because of their high sensitivity, selectivity and low response time. Among all the processes, developed for the synthesis of nanostructured metal oxides, gel combustion seems to be the most promising route due to low-cost precursors and simplicity of the process. It combines chemical gelation and combustion, involving the formation of a gel from an acqueous solution and an exothermic redox reaction, yielding to very porous and softly agglomerated nanopowders. In this work, nanostructured tin oxide, SnO2, and titanium oxide, TiO2, have been synthesized through gel combustion. Powders showed nanometric particle size and high specific surface area. The so-obtained TiO2 and SnO2 nanopowders have been used as sensitive element of resistive λ sensor and ethanol sensor respectively, realized depositing films of nanopowders dispersed in water onto alumina substrates provided with Pt contacts and heater. TiO2-based sensors showed at high temperature good response, fast response time, linearity in a wide range of O2 concentration and long-term stability. SnO2-based sensors have shown high sensitivity to low concentrations of ethanol at moderate temperature.

Download Full-text

A fully battery-powered inexpensive spectrophotometric system for high-sensitivity point-of-care analysis on a microfluidic chip

The Analyst ◽

10.1039/c6an00370b ◽

2016 ◽

Vol 141 (12) ◽

pp. 3898-3903 ◽

Cited By ~ 15

Author(s):

Maowei Dou ◽

Juan Lopez ◽

Misael Rios ◽

Oscar Garcia ◽

Chuan Xiao ◽

...

Keyword(s):

Microfluidic Chip ◽

Point Of Care ◽

Low Cost ◽

High Sensitivity ◽

Power Supplies ◽

Low Resource Settings ◽

Low Resource ◽

External Power

A low-cost b̲a̲ttery-powered s̲pectrophotometric s̲ystem (BASS) was developed for high-sensitivity point-of-care analysis in low-resource settings on a microfluidic chip without relying on external power supplies.

Download Full-text

Toward point-of-care diagnostics of Candida auris

10.1101/2020.02.10.20021683 ◽

2020 ◽

Cited By ~ 1

Author(s):

Geoffrey Mulberry ◽

Sudha Chaturvedi ◽

Vishnu Chaturvedi ◽

Brian N. Kim

Keyword(s):

New York ◽

Real Time ◽

Real Time Pcr ◽

Positive Impact ◽

Point Of Care ◽

Low Cost ◽

High Sensitivity ◽

Clinical Samples ◽

Pcr Assay ◽

Candida Auris

AbstractCandida auris is a multidrug-resistant yeast that presents global health threat for the hospitalized patients. Early diagnostic of C. auris is crucial in control, prevention, and treatment. Candida auris is difficult to identify with standard laboratory methods and often can be misidentified leading to inappropriate management. A newly-devised real-time PCR assay played an important role in the ongoing investigation of the C. auris outbreak in New York metropolitan area. The assay can rapidly detect C. auris DNA in surveillance and clinical samples with high sensitivity and specificity, and also useful for confirmation of C. auris cultures. Despite its positive impact, the real-time PCR assay is difficult to deploy at frontline laboratories due to high-complexity set-up and operation. Using a low-cost handheld real-time PCR device, we show that the C. auris can potentially be identified in a low-complexity assay without the need for high-cost equipment. An implementation of low-cost real-time PCR device in hospitals and healthcare facilities is likely to accelerate the diagnosis of C. auris and for control of the global epidemic.

Download Full-text

PCB-Based Magnetometer as a Platform for Quantification of Lateral-Flow Assays

Sensors ◽

10.3390/s19245433 ◽

2019 ◽

Vol 19 (24) ◽

pp. 5433 ◽

Cited By ~ 3

Author(s):

Mohammad Khodadadi ◽

Long Chang ◽

João R. C. Trabuco ◽

Binh V. Vu ◽

Katerina Kourentzi ◽

...

Keyword(s):

High Precision ◽

Fe3o4 Nanoparticles ◽

Printed Circuit Board ◽

Test Line ◽

Point Of Care ◽

Low Cost ◽

Superparamagnetic Iron Oxide ◽

High Sensitivity ◽

Lateral Flow ◽

Circuit Board

This work presents a proof-of-concept demonstration of a novel inductive transducer, the femtoMag, that can be integrated with a lateral-flow assay (LFA) to provide detection and quantification of molecular biomarkers. The femtoMag transducer is manufactured using a low-cost printed circuit board (PCB) technology and can be controlled by relatively inexpensive electronics. It allows rapid high-precision quantification of the number (or amount) of superparamagnetic nanoparticle reporters along the length of an LFA test strip. It has a detection limit of 10−10 emu, which is equivalent to detecting 4 ng of superparamagnetic iron oxide (Fe3O4) nanoparticles. The femtoMag was used to quantify the hCG pregnancy hormone by quantifying the number of 200 nm magnetic reporters (superparamagnetic Fe3O4 nanoparticles embedded into a polymer matrix) immuno-captured within the test line of the LFA strip. A sensitivity of 100 pg/mL has been demonstrated. Upon further design and control electronics improvements, the sensitivity is projected to be better than 10 pg/mL. Analysis suggests that an average of 109 hCG molecules are needed to specifically bind 107 nanoparticles in the test line. The ratio of the number of hCG molecules in the sample to the number of reporters in the test line increases monotonically from 20 to 500 as the hCG concentration increases from 0.1 ng/mL to 10 ng/mL. The low-cost easy-to-use femtoMag platform offers high-sensitivity/high-precision target analyte quantification and promises to bring state-of-the-art medical diagnostic tests to the point of care.

Download Full-text

Synthesis and Characterization of Mixed-Halide Inorganic-Organic Hybrid CH3NH3PbBr2.5Cl0.5 Perovskite for Photodetector Application

Journal of Nanoelectronics and Optoelectronics ◽

10.1166/jno.2021.2986 ◽

2021 ◽

Vol 16 (5) ◽

pp. 707-714

Author(s):

Yan Chen ◽

Siwen Tao ◽

Yaqi Liu ◽

Xuewei Fu ◽

Mengyi Pei ◽

...

Keyword(s):

Light Intensity ◽

Visible Light ◽

Single Crystal ◽

Bias Voltage ◽

Metal Ion ◽

Low Cost ◽

Visible Region ◽

High Sensitivity ◽

Photocurrent Density ◽

Organic Hybrid

Inorganic-organic hybrid perovskite (ABX3, A = organic cation, B = metal ion, X = halogen anion) combines the advantages of inorganic and organic materials. However, the properties and performance of mixed-halide CH3NH3PbBr2.5Cl0.5 (MAPbBr2.5Cl0.5) are still poorly understood. In this study, we synthetized MAPbBr2.5Cl0.5 single crystal and studied its structure, optical, thermal stability properties and optoelectronics applications for photodetector device. Compared with those of MAPbCl3, the interplanar distance of (100) crystal plane for MAPbBr2.5Cl0.5 becomes larger and the absorption spectrum of MAPbBr2.5Cl0.5 is extended to the visible region. The band gap of the MAPbBr2.5Cl0.5 single crystal is 2.28 eV. We find the device based on MAPbBr2.5Cl0.5 has high selectivity from 369 to 564 nm. The maximum ▴J (Jon– Joff) under 3.0 V bias voltage is about 1.2 µAcmr-2 at 454 nm visible light with 1 W mr-2 light intensity (1/1000 of the standard sunlight intensity), which proves the device has a high sensitivity. The linear relationship is established between the value of ▴J and light intensity and bias voltage. The fast current intensity transients (Fit) shows that the disappearance period of photocurrent density is 0.3 ms, which indicates the device is rapidly responsive photodetector. The highest value (1.7%) of external quantum efficiency (EQE) and the highest value of detectivities (D) both appear at 480 nm visible light at 4.0 V bias voltage when the irradiation power is 30 W m-2. Therefore, this simple and low-cost photoresponsive device is promising for industrial production of photodetector and photocatalysts device in the future.

Download Full-text