Cotton thread-based wearable sensor for non-invasive simultaneous diagnosis of diabetes and kidney failure

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Highlights

  • CNFs/chitosan-GO modified thread was prepared as non-invasive glucose and urea sensor.

  • CNFs improved the absorption behavior for chitosan-GO on the cotton thread surface.

  • Chitosan-GO increased thread surface area for enzymatic immobilization and thus sensor performances.

  • This sensor was applied for simultaneous detection of glucose and urea in sweat.

  • This platform can successfully differentiate between the normal and abnormal people.

Abstract

Thread has become a promising substrate for non-invasive wearable sensor. Herein, we create a modified cotton thread-based colorimetric sensor for non-invasive and simultaneous detection of glucose and urea excreted from human sweat. Cellulose nanofiber/chitosan-graphene oxide was selected to modify the cotton thread surfaces for enhancing of enzymatic immobilization efficiency and sensor performance. The modified thread surfaces were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. This sensing platform exhibits a linear range of 0.1–3 mM with a detection limit of 0.1 mM for glucose and a linear range of 30–180 mM with a detection limit of 30 mM for urea. Interestingly, this colorimetric sensor can determine the cut-off levels for both glucose (0.3 mM) and urea (65 mM) in human sweat, thus it can effectively distinguish between normal and abnormal people. Due to the thread flexibility nature, this sensor can be readily integrated with the clothes and accessories for real-time and continuous monitoring of diabetes and kidney failure from the wearer’s sweat. This platform might open a new road for blood-free diagnosis in healthcare applications.

Introduction

Nowadays, non-invasive or blood-free diagnosis is gained more attention for health status monitoring since it can reduce the pain and several risk factors compared with the traditional invasive diagnosis. The platform of non-invasive diagnosis can be designed and miniaturized to be wearable, comfortable and suitable for real-time and continuous monitoring. Several researchers have developed the wearable sensors for non-invasive analysis with various designs, such as eyeglasses [1], contact lenses [2,3], wristbands [4], mouthguards [5], gloves [6] and tattoos [[7], [8], [9]], which were directly contact with the human skin and human body. Thus, the requirements of the substrates for wearable sensors are light, flexible, stretchable, comfortable and biocompatible to human skin.

Various substrates, including paper [10], textile [[11], [12], [13]] and synthetic polymer [8,14,15] have been used for non-invasive sensor fabrication. Among all, the textile seems to be a promising one owing to its small size, high flexibility, non-skin irritation, low-cost, and easy-to-use as a self-microfluidic device [16]. Recently, our group reported on the use of cotton fabric as a substrate for a non-invasive sweat sensor, which can be used for the simultaneous detection of pH and lactate during the physical exercise [11]. In addition to the fabric sensor, thread has been also developed for non-invasive wearable sensors. Thread can be fabricated as an auto-microfluidic device by generating thread capillary channel from the gaps between fibers to make the fluids flow easily through the thread length [17,18]. The cotton thread is considered as a promising candidate for biosensor substrate since it requires ultra-low volume of the sample, and its surface can be readily modified for fast reaction time and high sensitivity [19,20].

Sweat is a biological fluid excreted from the human skin that can be used for non-invasive analysis. It contains electrolytes (e.g. sodium, chlorides, potassium and calcium), metabolites (e.g. lactate, creatinine, glucose, and uric acid), small molecules (e.g. amino acid, urea and cortisol) and proteins (e.g. interleukins, tumor necrosis factors and neuropeptide) [11]. These chemical compositions of sweat can be used as the biomarkers for indicating of the human health status [1,[7], [8], [9], [10], [11],13]. Among the sweat biomarkers, glucose and urea are the two crucial biomarkers since they can indicate diabetes and kidney status, respectively [21].

Diabetes is one of the fastest growing global health emergencies. In 2019, the International Diabetes Federation (IDF) estimated that 463 million people contain diabetes, and this number is projected to reach 700 million by 2045 [22]. Likewise, diabetes is one of the most non-communication chronic diseases in Thailand’s healthcare system. In 2017, the IDF projected that the number of Thai people with diabetes in 2040 will increase up to 5.3 million [23,24]. Furthermore, people with long term diabetes has a high potential risk of other complications, such as kidney failure and lower limb amputation. In 2006, the report from Thailand Diabetes Project indicates that most people with diabetes also suffered from kidney disease [23,24]. Hence, the simultaneous monitoring of urea indicating of kidney disease along with the diabetes is greatly desired. Importantly, the simultaneous monitoring of glucose and urea can effectively decrease both time and cost for clinical analysis.

Previously, various traditional analytical techniques (e.g. colorimetric, electrochemical, electroluminescent and ion detection) have been used to couple with non-invasive diagnosis in medical diagnosis [[7], [8], [9],11,25]. Among all, the colorimetry is the most practical one for self-monitoring because it is simple, inexpensive and self-detectable and readily interpretable by the naked eyes [8,[26], [27], [28], [29]]. Herein, we create a non-invasive thread based colorimetric wearable sensor for the simultaneous detection of glucose and urea in human sweat. This system can be readily integrated with the clothes or directly attached on the human skin as a novel blood-free wearable sensor for health monitoring.

Section snippets

Materials and reagents

The cotton threads (D·M·C®/BLANC) and candle wax were purchased from a local handicraft store (Bangkok, Thailand). Highly concentrated graphene oxide dispersion in water (GO) was purchased from Graphene Supermarket (New York, USA). Cellulose nanofiber (CNFs) dispersion in water was prepared and characterized by Prof. Aht-ong, D’s research group, department of material science, faculty of science, Chulalongkorn University. Glucose oxidase from Aspergillus niger, Type II, ≥15,000 units/g solid

Results and discussion

Principally, the sensing mechanism of this system relied on the color change caused by the enzymatic reaction and the chromogenic reagent reaction for both glucose and urea detection. For glucose, potassium iodide (KI) was used as a chromogenic agent while GOx and HRP are the bienzymatic system used to catalyze the glucose and KI reaction. When glucose excreted from sweat flow through the thread to the glucose detection zone, GOx catalyzed glucose to generate H2O2 and gluconic acid. Then HRP

Conclusions

The cotton thread based colorimetric sensor was successfully created by coating the CNFs/chitosan-GO composite and the enzymatic assays on the cotton thread surfaces. The presence of CNFs on the first layer improved the absorption behavior of the thread, while GO increased both specific surface area and surface functionality for enzymatic immobilization. The incorporation of chitosan on the thread can act as an enzyme supporter to provide a good microenvironment, leading to improved color

CRediT authorship contribution statement

Nadtinan Promphet: Investigation, Writing - original draft. Juan P. Hinestroza: Resources. Pranee Rattanawaleedirojn: Methodology, Writing - review & editing. Niphaphun Soatthiyanon: Writing - review & editing. Krisana Siralertmukul: Resources. Pranut Potiyaraj: Supervision. Nadnudda Rodthongkum: Conceptualization, Supervision, Writing - review & editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

Dr. Nadnudda Rodthongkum and Dr. Nadtinan Promphet would like to acknowledge The Second Century Fund (C2F), Chulalongkorn University. This research was financially supported by Chulalongkorn University (CU_GR_62_04_62_01). The authors would like to thank Prof. Duangdao Aht-ong’s research group, Department of Materials Science, Faculty of Science, Chulalongkorn University for providing the cellulose nanofibers for this research.

Nadtinan Promphet is a postdoctoral researcher at Metallurgy and Materials Science Research Institute, Chulalongkorn University. She received her Ph.D. degree (2019) in nanoscience and technology from Chulalongkorn University. Her current research interest focuses on the wearable bio/chemical sensors for biomolecule detection.

References (41)

  • Y. Wu et al.

    Clinical chemistry measurements with commercially available test slides on a smartphone platform: Colorimetric determination of glucose and urea

    Clin. Chim. Acta

    (2015)
  • R. Li et al.

    A novel glucose colorimetric sensor based on intrinsic peroxidase-like activity of C60-carboxyfullerenes

    Biosens. Bioelectron.

    (2013)
  • A. Soni et al.

    Smartphone based optical biosensor for the detection of urea in saliva

    Sens. Actuators B Chem.

    (2018)
  • X. Ye et al.

    A knittable fibriform supercapacitor based on natural cotton thread coated with graphene and carbon nanoparticles

    Electrochim. Acta

    (2016)
  • W. Dang et al.

    Stretchable wireless system for sweat pH monitoring

    Biosens. Bioelectron.

    (2018)
  • J.R. Sempionatto et al.

    Eyeglasses based wireless electrolyte and metabolite sensor platform

    Lab. Chip

    (2017)
  • M. Elsherif et al.

    Wearable contact Lens biosensors for continuous glucose monitoring using smartphones

    ACS Nano

    (2018)
  • R.C. Tseng et al.

    Contact-lens biosensors

    Sensors

    (2018)
  • W. Gao et al.

    Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

    Nat.

    (2016)
  • R.K. Mishra et al.

    Wearable flexible and stretchable glove biosensor for on-site detection of organophosphorus chemical threats

    ACS Sens.

    (2017)
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    Nadtinan Promphet is a postdoctoral researcher at Metallurgy and Materials Science Research Institute, Chulalongkorn University. She received her Ph.D. degree (2019) in nanoscience and technology from Chulalongkorn University. Her current research interest focuses on the wearable bio/chemical sensors for biomolecule detection.

    Juan P. Hinestroza is a Professor of Fiber Science and directs The Textiles Nanotechnology Laboratory at the College of Human Ecology of Cornell University in Ithaca, NY. He obtained his Ph.D. from the Department of Chemical and Biomolecular Engineering at Tulane University and B.Sc. in Chemical Engineering from Universidad Industrial de Santander. His current research interests in the field of smart and interactive textiles and fibers.

    Pranee Rattanawaleedirojn is currently a researcher at Metallurgy and Materials Science Research Institute, Chulalongkorn University. She obtained her M.Sc. in Applied Polymer Science and Textile Technology and B.Sc. in Chemistry. Her current research interest focuses on the smart textile and surface coating technology.

    Niphaphun Soatthiyanon obtained her Ph.D. degree in Materials Science and Engineering, University of New South Wales, Sydney, NSW, Australia. Her current research interest focuses on cellulose based materials and its application in polymer processing.

    Krisana Siralertmukul is a researcher and lecturer at Chulalongkorn University. She received her Ph.D. degree in material science from Chulalongkorn University. Her research interest focuses on the biopolymer and its application.

    Pranut Potiyaraj is a professor in materials science department and director of Metallurgy and Materials Science Research Institute, Chulalongkorn University. He obtained his Ph.D. in textiles from University of Manchester Institute of Science and Technology (UMIST), UK. His research interest focuses on biopolymer and textiles.

    Nadnudda Rodthongkum is a researcher and deputy director of Metallurgy and Materials Science Research Institute, Chulalongkorn University. She obtained her Ph.D. in chemistry from University of Massachusetts, Amherst, USA. Her research interest focuses on design of new materials for analytical applications.

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