Wearable optical patches for non-invasive sweat sensing

Abstract

As a non-invasive and information-rich diagnostic biofluid, sweat offers a promising alternative to conventional blood analysis, circumventing issues of invasiveness, patient discomfort, and complex laboratory processing. Wearable optical patches for non-invasive sweat sensing are emerging as a transformative platform in personalized and preventive healthcare, enabling real-time, continuous monitoring of metabolic and electrolyte biomarkers. This review comprehensively summarizes recent advances in wearable flexible optical sweat sensors, focusing on the following primary optical mechanisms: colorimetry, surface-enhanced Raman scattering, fluorescence, electrochemiluminescence and other optical approaches. First, we discuss the integration of these sensing modalities with soft, stretchable substrates, such as hydrogels, textiles, paper, and polymer films, and highlight key innovations in sweat collection, fabrication techniques, adhesion, and encapsulation that enable robust wearable operation. Second, we examine performance metrics, current challenges, and future perspectives for translating these technologies from laboratory prototypes to clinical and commercial applications. Finally, the challenges and future perspectives of the next-generation wearable optical platforms for continuous sweat analysis and personalized health monitoring are discussed.

Keywords

Flexible optical sensors / sweat metabolites / colorimetry / fluorescence / electrochemiluminescence

References

[1] Manjakkal L.,Yin L.,Nathan A.,Wang J.,Dahiya R.. Energy autonomous sweat-based wearable systems Adv. Mater. 2021 33 e2100899 PMC11481680

[2] Karpova E. V.,Karyakina E. E.,Karyakin A. A.. Wearable non-invasive monitors of diabetes and hypoxia through continuous analysis of sweat Talanta 2020 215 120922

[3] Bariya M.,Nyein H. Y. Y.,Javey A.. Wearable sweat sensors Nat. Electron. 2018 1 160 71

[4] Sharma A.,Badea M.,Tiwari S.,Marty J. L.. Wearable biosensors: an alternative and practical approach in healthcare and disease monitoring Molecules 2021 26 748 PMC7867046

[5] Smith A. A.,Li R.,Tse Z. T. H.. Reshaping healthcare with wearable biosensors Sci. Rep. 2023 13 4998 PMC10043012

[6] Xu J.,Fang Y.,Chen J.. Wearable biosensors for non-invasive sweat diagnostics. Biosensors 2021, 11, 245 PMC8391966

[7] Song Z.,Zhou S.,Qin Y..et al. Flexible and wearable biosensors for monitoring health conditions Biosensors 2023 13 630 PMC10296135

[8] Vo D. K.,Trinh K. T. L.. Advances in wearable biosensors for healthcare: current trends, applications, and future perspectives Biosensors 2024 14 560 PMC11592256

[9] Ghaffari R.,Yang D. S.,Kim J..et al. State of sweat: emerging wearable systems for real-time, noninvasive sweat sensing and analytics ACS Sens. 2021 6 2787 801 PMC9108092

[10] Nonaka T.,Wong D. T. W.. Saliva diagnostics Annu. Rev. Anal. Chem. (Palo Alto. Calif). 2022 15 107 21 PMC9348814

[11] Song M.,Bai H.,Zhang P.,Zhou X.,Ying B.. Promising applications of human-derived saliva biomarker testing in clinical diagnostics Int. J. Oral Sci. 2023 15 2 PMC9810734

[12] Ghelli F.,Panizzolo M.,Garzaro G..et al. Inflammatory biomarkers in exhaled breath condensate: a systematic review Int. J. Mol. Sci. 2022 23 9820 PMC9456215

[13] Szunerits S.,Dӧrfler H.,Pagneux Q..et al. Exhaled breath condensate as bioanalyte: from collection considerations to biomarker sensing Anal. Bioanal. Chem. 2023 415 27 34 PMC9672542

[14] Dos Santos C. C.,Lucena G. N.,Pinto G. C.,Júnior M. J.,Marques R. F.. Advances and current challenges in non‐invasive wearable sensors and wearable biosensors - a mini‐review Med. Devices. Sens. 2020 4 e10130

[15] Ma C. B.,Shang X.,Sun M..et al. Emerging multifunctional wearable sensors: integrating multimodal sweat analysis and advanced material technologies for next-generation health monitoring ACS Sens. 2025 10 2388 408

[16] Luo D.,Sun H.,Li Q.,Niu X.,He Y.,Liu H.. Flexible sweat sensors: from films to textiles ACS Sens. 2023 8 465 81

[17] Pour S. R. S.,Calabria D.,Emamiamin A..et al. Microfluidic-based non-invasive wearable biosensors for real-time monitoring of sweat biomarkers Biosensors 2024 14 29 PMC10813635

[18] Xuan X.,Pérez-Ràfols C.,Chen C.,Cuartero M.,Crespo G. A.. Lactate biosensing for reliable on-body sweat analysis ACS Sens. 2021 6 2763 71 PMC8397467

[19] Davis N.,Heikenfeld J.,Milla C.,Javey A.. The challenges and promise of sweat sensing Nat. Biotechnol. 2024 42 860 71

[20] Jo S.,Sung D.,Kim S.,Koo J.. A review of wearable biosensors for sweat analysis Biomed. Eng. Lett. 2021 11 117 29 PMC8155147

[21] Yang D. S.,Ghaffari R.,Rogers J. A.. Sweat as a diagnostic biofluid Science 2023 379 760 1

[22] Marvelli A.,Campi B.,Mergni G..et al. Sweat chloride assay by inductively coupled plasma mass spectrometry: a confirmation test for cystic fibrosis diagnosis Anal. Bioanal. Chem. 2020 412 6909 16 PMC7495987

[23] Aloke C.,Egwu C. O.,Aja P. M..et al. Current advances in the management of diabetes mellitus Biomedicines 2022 10 2436 PMC9599361

[24] Huang T.,Liang Z.,Wang K.,Miao X.,Zheng L.. Novel insights into athlete physical recovery concerning lactate metabolism, lactate clearance and fatigue monitoring: a comprehensive review Front. Physiol. 2025 16 1459717 PMC11975961

[25] Knezevic E.,Nenic K.,Milanovic V.,Knezevic N. N.. The role of cortisol in chronic stress, neurodegenerative diseases, and psychological disorders Cells 2023 12 2726 PMC10706127

[26] Pulopulos M. M.,Baeken C.,De Raedt R.. Cortisol response to stress: The role of expectancy and anticipatory stress regulation Horm. Behav. 2020 117 104587

[27] Ghaffari R.,Rogers J. A.,Ray T. R.. Recent progress, challenges, and opportunities for wearable biochemical sensors for sweat analysis Sens. Actuators. B. Chem. 2021 332 129447 PMC7853653

[28] Heng W.,Yang G.,Kim W. S.,Xu K.. Emerging wearable flexible sensors for sweat analysis Bio-des. Manuf. 2022 5 64 84

[29] Choi D. H.,Kitchen G. B.,Stewart K. J.,Searson P. C.. The dynamic response of sweat chloride to changes in exercise load measured by a wearable sweat sensor Sci. Rep. 2020 10 7699 PMC7205967

[30] Lihong Z.,Qiuping L.. Advancements and obstacles in sweat-based biosensors for health monitoring Crit. Rev. Anal. Chem. 2025 1 32

[31] Yu H.,Sun J.. Sweat detection theory and fluid driven methods: a review Nanotechnol. Precis. Eng. 2020 3 126 40

[32] Brasier N.,Eckstein J.. Sweat as a source of next-generation digital biomarkers Digit. Biomark. 2020 3 155 65 PMC7011725

[33] Tang Y.,Li X.,Lv H.,Wang W.,Zhi C.,Li H.. Integration designs toward new‐generation wearable energy supply‐sensor systems for real‐time health monitoring: a minireview InfoMat 2020 2 1109 30

[34] Johnson K. B.,Wei W. Q.,Weeraratne D..et al. Precision medicine, AI, and the future of personalized health care Clin. Transl. Sci. 2021 14 86 93 PMC7877825

[35] Iqbal S. M. A.,Mahgoub I.,Du E.,Leavitt M. A.,Asghar W.. Advances in healthcare wearable devices NPJ Flex. Electron. 2021 5 9

[36] Hu M.,Wang Z.,Zhang L.,Lin S.,Liao J.. A microfluidic patch for wireless wearable electrochemical detection of sweat metabolites Sens. Actuators. B. Chem. 2025 422 136604

[37] Bilbao E.,Garate O.,Rodríguez Campos T..et al. Electrochemical sweat sensors Chemosensors 2023 11 244

[38] Liu G.,Wang H.,Zhang P..et al. A wearable multi-parameter electrochemical detection and signal processing system for real-time sweat analysis Mikrochim. Acta 2025 192 604

[39] Childs A.,Mayol B.,Lasalde-Ramírez J. A.,Song Y.,Sempionatto J. R.,Gao W.. Diving into sweat: advances, challenges, and future directions in wearable sweat sensing ACS Nano 2024 18 24605 16 PMC12129723

[40] Gao N.,Xu G.,Chang G.,Wu Y.. From lab to life: self-powered sweat sensors and their future in personal health monitoring Adv. Sci. (Weinh). 2025 12 e2409178 PMC12199596

[41] Wang X.,Shen C.,Zhou C.,Bu Y.,Yan X.. Methods, principles and applications of optical detection of metal ios Chem. Eng. J. 2021 417 129125

[42] Kumar S.,Singh R.. Recent optical sensing technologies for the detection of various biomolecules: review Opt. Laser Technol. 2021 134 106620

[43] Wang J.,Luo Y.,Zhou Z.,Xiao J.,Xu T.,Zhang X.. Epidermal wearable optical sensors for sweat monitoring Commun. Mater. 2024 5 77

[44] Qin J.,Jiang S.,Wang Z..et al. Metasurface micro/nano-optical sensors: principles and applications ACS Nano 2022 16 11598 618

[45] Min J.,Tu J.,Xu C..et al. Skin-interfaced wearable sweat sensors for precision medicine Chem. Rev. 2023 123 5049 138 PMC10406569

[46] Vasanth A.,Ashok A.,Do T. N.,Phan H. P.. Advancements in flexible porous nanoarchitectonic materials for biosensing applications Adv. Colloid Interface Sci. 2025 339 103439

[47] Ariati R.,Sales F.,Souza A.,Lima R. A.,Ribeiro J.. Polydimethylsiloxane composites characterization and its applications: a review Polymers (Basel). 2021 13 4258 PMC8659928

[48] Teixeira I.,Castro I.,Carvalho V..et al. Polydimethylsiloxane mechanical properties: a systematic review AIMS Mater. Sci. 2021 8 952 73

[49] Choi J.,Xue Y.,Xia W..et al. Soft, skin-mounted microfluidic systems for measuring secretory fluidic pressures generated at the surface of the skin by eccrine sweat glands Lab Chip 2017 17 2572 80 PMC5561737

[50] Koh A.,Kang D.,Xue Y..et al. A soft, wearable microfluidic device for the capture, storage, and colorimetric sensing of sweat Sci. Transl. Med. 2016 8 366ra165 PMC5429097

[51] Lima R. A.. The impact of polydimethylsiloxane (PDMS) in engineering: recent advances and applications Fluids 2025 10 41

[52] Kan X.,Shi E.,Zhu C.,Wang Q.,Qu L.,Dong X.. Binary solvent-induced ultra-adhesive gel for underwater motion and water flow detection ACS Appl. Polym. Mater. 2025 7 6523 32

[53] Qu X.,Wang Q.,Gan D.,Sun H.,Ni Z.,Dong X.. Tissue-adaptable hydrogel for mechanically compliant bioelectronic interfaces Nano Lett. 2025 25 4759 66

[54] Hu B.,Kang X.,Xu S.,Zhu J.,Yang L.,Jiang C.. Multiplex chroma response wearable hydrogel patch: visual monitoring of urea in body fluids for health prognosis Anal. Chem. 2023 95 3587 95

[55] Wang W.,Chen Y.,Xiao C..et al. Flexible SERS wearable sensor based on nanocomposite hydrogel for detection of metabolites and pH in sweat Chem. Eng. J. 2023 474 145953

[56] Sun H.,Qu X.,Wang Q.,Guo Y.,Dong X.. Dynamic regulation of interfacial adhesion in biomedical hydrogels Chem. Soc. Rev. 2026 55 469 503

[57] Qu X.,Wang Q.,Sun H..et al. Molecular competition induced Janus hydrogel bioelectronic interface for electroceutical modulation Nat. Commun. 2025 17 455 PMC12800210

[58] Chao F.,Cao C.,Xu Y..et al. Sprayable hydrogel for pH-responsive nanozyme-derived bacteria-infected wound healing ACS Appl. Mater. Interfaces 2025 17 5921 32

[59] Gan D.,Wang Q.,Zhang X..et al. Congeneric and robust adhesive epidermal patch for anti-interference physiological signal recognition Adv. Funct. Mater. 2024 34 2411588

[60] Shao Z.,Chen H.,Wang Q..et al. Melt electrowriting ordered TPU microfibrous mesh for on-demand colorimetric wearable sweat detection IEEE Sensors J. 2022 22 18560 6

[61] Sheng F.,Zhao C.,Zhang B.,Tan Y.,Dong K.. Flourishing electronic textiles towards pervasive, personalized and intelligent healthcare Soft Sci. 2024 4 2

[62] Hou Z.,Liu X.,Tian M..et al. Smart fibers and textiles for emerging clothe-based wearable electronics: materials, fabrications and applications J. Mater. Chem. A. 2023 11 17336 72

[63] Zhang Y.,Wang H.,Lu H.,Li S.,Zhang Y.. Electronic fibers and textiles: recent progress and perspective iScience 2021 24 102716 PMC8258642

[64] Zhang S.,Tan R.,Xu X.,Iqbal S.,Hu J.. Fibers/textiles-based flexible sweat sensors: a review ACS Materials Lett. 2023 5 1420 40

[65] Koh E. H.,Lee W. C.,Choi Y. J..et al. A wearable surface-enhanced raman scattering sensor for label-free molecular detection ACS Appl. Mater. Interfaces 2021 13 3024 32

[66] Han Y.,Fang X.,Li H.,Zha L.,Guo J.,Zhang X.. Sweat sensor based on wearable janus textiles for sweat collection and microstructured optical fiber for surface-enhanced raman scattering analysis ACS Sens. 2023 8 4774 81

[67] Mogera U.,Guo H.,Namkoong M.,Rahman M. S.,Nguyen T.,Tian L.. Wearable plasmonic paper-based microfluidics for continuous sweat analysis Sci. Adv. 2022 8 eabn1736 PMC8942375

[68] Khan S. M.,Nassar J. M.,Hussain M. M.. Paper as a substrate and an active material in paper electronics ACS Appl. Electron. Mater. 2020 3 30 52

[69] Eskandari V.,Sahbafar H.,Zeinalizad L.,Marashipour R.,Hadi A.. A review of paper-based substrates as surface-enhanced Raman spectroscopy (SERS) biosensors and microfluidic paper-based SERS platforms J. Comput. Appl. Mech. 2022 53 142 56

[70] Chung M.,Skinner W. H.,Robert C..et al. Fabrication of a wearable flexible sweat pH sensor based on SERS-active Au/TPU electrospun nanofibers ACS Appl. Mater. Interfaces 2021 13 51504 18

[71] Jeon J.,Lee S.,Chae S..et al. All-flexible chronoepifluidic nanoplasmonic patch for label-free metabolite profiling in sweat Nat. Commun. 2025 16 8017 PMC12391418

[72] Fan F.,Chen L.,Wang Y..et al. Damage-free dry transfer printing of ultrathin films with on-demand interfacial adhesion: principles and applications Soft Sci. 2025 5 52

[73] Chen S.,Qiao Z.,Niu Y..et al. Wearable flexible microfluidic sensing technologies Nat. Rev. Bioeng. 2023 1 950 71

[74] Ayuso J. M.,Virumbrales-Muñoz M.,Lang J. M.,Beebe D. J.. A role for microfluidic systems in precision medicine Nat. Commun. 2022 13 3086 PMC9163169

[75] Ray T. R.,Choi J.,Bandodkar A. J..et al. bio-integrated wearable systems: a comprehensive review Chem. Rev. 2019 119 5461 533

[76] Baker L. B.,Model J. B.,Barnes K. A..et al. Skin-interfaced microfluidic system with personalized sweating rate and sweat chloride analytics for sports science applications Sci. Adv. 2020 6 eabe3929 PMC7732194

[77] Vaquer A.,Barón E.,de la Rica R.. Wearable analytical platform with enzyme-modulated dynamic range for the simultaneous colorimetric detection of sweat volume and sweat biomarkers ACS Sens. 2021 6 130 6

[78] Villa J. E. L.,Garcia I.,Jimenez de Aberasturi D.,Pavlov V.,Sotomayor M. D. P. T.,Liz-Marzán L. M.. SERS-based immunoassay for monitoring cortisol-related disorders Biosens. Bioelectron. 2020 165 112418

[79] Ardalan S.,Hosseinifard M.,Vosough M.,Golmohammadi H.. Towards smart personalized perspiration analysis: an IoT-integrated cellulose-based microfluidic wearable patch for smartphone fluorimetric multi-sensing of sweat biomarkers Biosens. Bioelectron. 2020 168 112450

[80] Li H.,Ma Y.,Huang Y.. Material innovation and mechanics design for substrates and encapsulation of flexible electronics: a review Mater. Horiz. 2021 8 383 400

[81] Tu J.,Yeom J.,Ulloa J. C..et al. Stressomic: A wearable microfluidic biosensor for dynamic profiling of multiple stress hormones in sweat Sci. Adv. 2025 11 eadx6491 PMC12327446

[82] Luo Y.,Abidian M. R.,Ahn J. H..et al. Technology roadmap for flexible sensors ACS Nano 2023 17 5211 95 PMC11223676

[83] Deng M. Z.,Zhong M. Y.,Li M. L..et al. Research progress on electrochemiluminescence nanomaterials and their applications in biosensors - a review Anal. Chim. Acta 2025 1361 344148

[84] Kim J.,Oh S.,Yang D. S..et al. A skin-interfaced, miniaturized platform for triggered induction, capture and colorimetric multicomponent analysis of microliter volumes of sweat Biosens. Bioelectron. 2024 253 116166

[85] Liu S.,Yang D. S.,Wang S..et al. Soft, environmentally degradable microfluidic devices for measurement of sweat rate and total sweat loss and for colorimetric analysis of sweat biomarkers EcoMat 2022 5 e12270

[86] Liu Z.,Li J.,Li J..et al. Explainable deep-learning-assisted sweat assessment via a programmable colorimetric chip Anal. Chem. 2022 94 15864 72

[87] Zheng X. T.,Goh W. P.,Yu Y..et al. Skin-attachable ink-dispenser-printed paper fluidic sensor patch for colorimetric sweat analysis Adv. Healthc. Mater. 2024 13 e2302173

[88] Cheng Y.,Feng S.,Ning Q..et al. Dual-signal readout paper-based wearable biosensor with a 3D origami structure for multiplexed analyte detection in sweat Microsyst. Nanoeng. 2023 9 36 PMC10042807

[89] Kim J.,Wu Y.,Luan H..et al. A skin-interfaced, miniaturized microfluidic analysis and delivery system for colorimetric measurements of nutrients in sweat and supply of vitamins through the skin Adv. Sci. (Weinh). 2022 9 e2103331 PMC8805554

[90] Ghaffari R.,Choi J.,Raj M. S..et al. soft wearable systems for colorimetric and electrochemical analysis of biofluids Adv. Funct. Mater. 2019 30 1907269

[91] Xi P.,He X.,Fan C..et al. Smart Janus fabrics for one-way sweat sampling and skin-friendly colorimetric detection Talanta 2023 259 124507

[92] Kwon K.,Kim J. U.,Deng Y..et al. An on-skin platform for wireless monitoring of flow rate, cumulative loss and temperature of sweat in real time Nat. Electron. 2021 4 302 12

[93] Sung D.,Han S.,Kim S..et al. Electrophoretic digital colorimetry integrated with electrochemical sweat sensor Sci. Adv. 2025 11 eadu2142 PMC11952109

[94] Gui X.,Xie J.,Wang W..et al. Wearable and flexible nanoporous surface-enhanced raman scattering substrates for sweat enrichment and analysis ACS Appl. Nano Mater. 2023 6 11049 60

[95] Li G.,Fan X.,Tang X..et al. Challenges and prospects of personalized healthcare based on surface-enhanced Raman spectroscopy Research (Wash. D. C). 2024 7 0572 PMC12327435

[96] Liu X.,Ma J.,Jiang P..et al. Large-scale flexible surface-enhanced Raman scattering (SERS) sensors with high stability and signal homogeneity ACS Appl. Mater. Interfaces 2020 12 45332 41

[97] Xie L.,Zeng H.,Zhu J..et al. State of the art in flexible SERS sensors toward label-free and onsite detection: from design to applications Nano Res. 2022 15 4374 94

[98] Laing S.,Sloan-Dennison S.,Faulds K.,Graham D.. Surface enhanced Raman scattering for biomolecular sensing in human healthcare monitoring ACS Nano 2025 19 8381 400 PMC11912579

[99] He X.,Fan C.,Luo Y.,Xu T.,Zhang X.. Flexible microfluidic nanoplasmonic sensors for refreshable and portable recognition of sweat biochemical fingerprint NPJ Flex. Electron. 2022 6 60

[100] Lee G. H.,Moon H.,Kim H..et al. Multifunctional materials for implantable and wearable photonic healthcare devices Nat. Rev. Mater. 2020 5 149 65 PMC7388681

[101] Shin Y.,Teresa Gutierrez-wing M.,Choi J.. Review - recent progress in portable fluorescence sensors J. Electrochem. Soc. 2021 168 017502

[102] Sekine Y.,Kim S. B.,Zhang Y..et al. A fluorometric skin-interfaced microfluidic device and smartphone imaging module for in situ quantitative analysis of sweat chemistry Lab Chip 2018 18 2178 86

[103] Cho S. H.,Cho S.,Lv Z..et al. Soft, wearable, microfluidic system for fluorometric analysis of loss of amino acids through eccrine sweat Lab Chip 2025 25 1647 55 PMC11970843

[104] Cui Y.,Duan W.,Jin Y.,Wo F.,Xi F.,Wu J.. Ratiometric fluorescent nanohybrid for noninvasive and visual monitoring of sweat glucose ACS Sens. 2020 5 2096 105

[105] Chen Q.,Li S.,Tu X.,Zhang X.. Skin-attachable Tb-MOF ratio fluorescent sensor for real-time detection of human sweat pH Biosens. Bioelectron. 2024 263 116606

[106] Chen M. M.,Cheng S. B.,Ji K..et al. Construction of a flexible electrochemiluminescence platform for sweat detection Chem. Sci. 2019 10 6295 303 PMC6598512

[107] Ma X.,Gao W.,Du F..et al. Rational design of electrochemiluminescent devices Acc. Chem. Res. 2021 54 2936 45

[108] Chen Y.,Chen J.,Luo Y..et al. Stretchable photonic crystal-enhanced ECL for sweat neurotransmitter detection Anal. Chem. 2025 97 19525 31

[109] Ferraraccio L. S.,Bertoncello P.. Electrochemiluminescence (ECL) biosensor based on tris(2,2'-bipyridyl)ruthenium(II) with glucose and lactate dehydrogenases encapsulated within alginate hydrogels Bioelectrochemistry 2023 150 108365

[110] Cai X.,Yan J.,Chu H.,Wu M.,Tu Y.. An exercise degree monitoring biosensor based on electrochemiluminescent detection of lactate in sweat Sens. Actuators. B. Chem. 2010 143 655 9

[111] Hu Y.,Li J.,Liu J.,Yu X.,Yang J.,Li Y.. A simple yet multifunctional sensing platform inspired by healing-assembly hydrogels serving motion and sweat monitoring Sens. Actuators. B. Chem. 2023 378 133173

[112] Sun Y.,Li P.,Zhu Y..et al. In situ growth of TiO₂ nanowires on Ti₃C₂ MXenes nanosheets as highly sensitive luminol electrochemiluminescent nanoplatform for glucose detection in fruits, sweat and serum samples Biosens. Bioelectron. 2021 194 113600

[113] Kwon D. K.,Myoung J. M.. Wearable and semitransparent pressure-sensitive light-emitting sensor based on electrochemiluminescence ACS Nano 2020 14 8716 23

[114] Gomez D.. Fibre optic humidity and pH sensing for healthcare and sports applications Sens. Actuators B Chem. 2018 254 887 95 https://eprints.nottingham.ac.uk/55406/ (accessed 2026-2-27)

[115] Duarah R.,Torné-Morató H.,Zhang G..et al. Next-generation wearable optical sensors for personalized health and point-of-care diagnostics-a systematic review Adv. Healthc. Mater. 2026 e04419

[116] Zhang H.,Chen S.,Fan X..et al. The fiber optic SPR cholesterol biosensor based on electroless silver plating film Optics Laser Technol. 2025 192 113907

[117] Lei Y.,Gong Z.,Li Y..et al. Highly Sensitive physiological sensor based on tapered fiber-optic interferometer for sweat pH detection IEEE Sensors J. 2023 23 11627 34

[118] Karipbayeva K.,Blanc W.,Tosi D.. Optical fiber semi-distributed interferometer assisted by an FBG for thermorefractometry and sweat sensing IEEE Sensors J. 2023 23 14161 6

[119] Tu D.,Tang Y.,Huang Y..et al. Next-generation wearable/implanted sensors based on fiber optic and its application: from in vitro to in vivo ACS Sens. 2025 10 3818 39

[120] Zhang Z.,Li K.,Li Y.,Zhang Q.,Wang H.,Hou C.. Dual-function wearable hydrogel optical fiber for monitoring posture and sweat pH ACS Sens. 2024 9 3413 22

[121] Wang R.,Yang X.,Tian F..et al. Highly sensitive and rapid Raman detection of lactic acid in human sweat based on reflective tapered optical fiber Optics Laser Technol. 2025 188 112975

[122] Xiang L.,Zeng X.,Xia F.,Jin W.,Liu Y.,Hu Y.. Recent advances in flexible and stretchable sensing systems: from the perspective of system integration ACS Nano 2020 14 6449 69

[123] Yang Y.,Gao W.. Wearable and flexible electronics for continuous molecular monitoring Chem. Soc. Rev. 2019 48 1465 91

[124] Wang D.,Xu G.,Zhang X..et al. Dual-functional ultrathin wearable 3D particle-in-cavity SF-AAO-Au SERS sensors for effective sweat glucose and lab-on-glove pesticide detection Sens. Actuators. B. Chem. 2022 359 131512

[125] Kim H. S.,Kim H. J.,Lee J..et al. Hand-held Raman spectrometer-based dual detection of creatinine and cortisol in human sweat using silver nanoflakes Anal. Chem. 2021 93 14996 5004