Early detection of<i>E. coli</i>and total coliform using an automated, colorimetric and fluorometric fiber optics-based device

Tok, Sabiha; Haan, Kevin de; Tseng, Derek; Usanmaz, Can Firat; Koydemir, Hatice Ceylan; Ozcan, Aydogan

doi:10.1039/c9lc00652d

Cited by 28 publications

(16 citation statements)

References 35 publications

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“…For example, many of these reports include readers using low‐cost components, typically involving a mobile phone, mobile phones and other portable sensors (such as the popular Raspberry Pi camera platform). These low‐cost consumer‐grade optoelectronics have been explored as convenient platform for biomedical testing devices for several years, including microscopes , spectrometers , assay readers , among other uses . Due to their incorporation of on‐board computing, intuitive interfaces, wireless communication and relatively high quality imaging sensors, their attractiveness as the basis of a sensing platform is undeniable.…”

Section: Introductionmentioning

confidence: 99%

Improving the limit of detection in portable luminescent assay readers through smart optical design

Wang

et al. 2019

Journal of Biophotonics

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Critical biomarkers of disease are increasingly being detected by point‐of‐care assays. Chemiluminescence (CL) and electrochemiluminescence (ECL) are often used in such assays due to their convenience and that they do not require light sources or other components that could complicate or add cost to the system. Reports of these assays often include readers built on a cellphone platform or constructed from low‐cost components. However, the impact the optical design has on the limit of detection (LOD) in these systems remains unexamined. Here, we report a theoretical rubric to evaluate different optical designs in terms of maximizing the use of photons emitted from a CL or ECL assay to improve the LOD. We demonstrate that the majority of cellphone designs reported in the literature are not optimized, in part due to misunderstandings of the optical tradeoffs in collection systems, and in part due to limitations imposed on the designs arising from the use of a mobile phone with a very small lens aperture. Based on the theoretical rubric, we design a new portable reader built using off‐the‐shelf condenser optics, and demonstrate a nearly 10× performance enhancement compared to prior reports on an ECL assays running on a portable chip.

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Section: Introductionmentioning

confidence: 99%

Improving the limit of detection in portable luminescent assay readers through smart optical design

Wang

et al. 2019

Journal of Biophotonics

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“…The design of our mobile-phone based reader can be further improved to image multiple cuvettes all at the same time and can be automated to enable time-lapse imaging of samples to minimize operational time and associated costs. Finally, the imaging mode of this reader can be further integrated with other light sources to enable fluorescence based measurements 28 within the same design.…”

Section: Resultsmentioning

confidence: 99%

Smartphone-based turbidity reader

Koydemir¹,

Rajpal²,

Gumustekin³

et al. 2019

Sci Rep

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Water quality is undergoing significant deterioration due to bacteria, pollutants and other harmful particles, damaging aquatic life and lowering the quality of drinking water. It is, therefore, important to be able to rapidly and accurately measure water quality in a cost-effective manner using e.g., a turbidimeter. Turbidimeters typically use different illumination angles to measure the scattering and transmittance of light through a sample and translate these readings into a measurement based on the standard nephelometric turbidity unit (NTU). Traditional turbidimeters have high sensitivity and specificity, but they are not field-portable and require electricity to operate in field settings. Here we present a field-portable and cost effective turbidimeter that is based on a smartphone. This mobile turbidimeter contains an opto-mechanical attachment coupled to the rear camera of the smartphone, which contains two white light-emitting-diodes to illuminate the water sample, optical fibers to transmit the light collected from the sample to the camera, an external lens for image formation, and diffusers for uniform illumination of the sample. Including the smartphone, this cost-effective device weighs only ~350 g. In our mobile turbidimeter design, we combined two illumination approaches: transmittance, in which the optical fibers were placed directly below the sample cuvette at 180° with respect to the light source, and nephelometry in which the optical fibers were placed on the sides of the sample cuvette at a 90° angle with respect to the to the light source. Images of the end facets of these fiber optic cables were captured using the smart phone and processed using a custom written image processing algorithm to automatically quantify the turbidity of each sample. Using transmittance and nephelometric readings, our mobile turbidimeter achieved accurate measurements over a large dynamic range, from 0.3 NTU to 2000 NTU. The accurate performance of our smartphone-based turbidimeter was also confirmed with various water samples collected in Los Angeles (USA), bacteria spiked water samples, as well as diesel fuel contaminated water samples. Having a detection limit of ~0.3 NTU, this cost-effective smartphone-based turbidimeter can be a useful analytical tool for screening of water quality in resource limited settings.

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“…The use of characterized FO is of vital importance, since almost all research papers document improved sensitivity, managing to overcome Bland-Altman tests against established devices or gold standards to determine sensitivity and operation during laboratory tests. This not only for vital signs [63,91,105,115] but also for a wide variety of optical sensors for use in the medical field, such as bacteria sensors [122], glucose monitors [123], cardiovascular monitors [107] (although this research work fails to present conclusive results due to the small number of samples, but they prove to have better sensitivity values), diabetic foot treatment [124], and also in the field of biochemistry [125] as diagnostic sensors, environmental monitoring, and organic and chemical compounds.…”

Section: Discussionmentioning

confidence: 99%

Fiber Optic Sensors for Vital Signs Monitoring. A Review of Its Practicality in the Health Field

et al. 2021

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Vital signs not only reflect essential functions of the human body but also symptoms of a more serious problem within the anatomy; they are well used for physical monitoring, caloric expenditure, and performance before a possible symptom of a massive failure—a great variety of possibilities that together form a first line of basic diagnosis and follow-up on the health and general condition of a person. This review includes a brief theory about fiber optic sensors’ operation and summarizes many research works carried out with them in which their operation and effectiveness are promoted to register some vital sign(s) as a possibility for their use in the medical, health care, and life support fields. The review presents methods and techniques to improve sensitivity in monitoring vital signs, such as the use of doping agents or coatings for optical fiber (OF) that provide stability and resistance to the external factors from which they must be protected in in vivo situations. It has been observed that most of these sensors work with single-mode optical fibers (SMF) in a spectral range of 1550 nm, while only some work in the visible spectrum (Vis); the vast majority, operate through fiber Bragg gratings (FBG), long-period fiber gratings (LPFG), and interferometers. These sensors have brought great advances to the measurement of vital signs, especially with regard to respiratory rate; however, many express the possibility of monitoring other vital signs through mathematical calculations, algorithms, or auxiliary devices. Their advantages due to miniaturization, immunity to electromagnetic interference, and the absence of a power source makes them truly desirable for everyday use at all times.

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Early detection ofE. coliand total coliform using an automated, colorimetric and fluorometric fiber optics-based device

Abstract: We report early detection of E. coli and total coliform bacteria using an automated, colorimetric and fluorometric fiber optics-based device.

Cited by 28 publications

References 35 publications

Improving the limit of detection in portable luminescent assay readers through smart optical design

Improving the limit of detection in portable luminescent assay readers through smart optical design

Smartphone-based turbidity reader

Fiber Optic Sensors for Vital Signs Monitoring. A Review of Its Practicality in the Health Field

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