Food Analytical Methods

, Volume 12, Issue 2, pp 612–624 | Cite as

A Step Towards Miniaturized Milk Adulteration Detection System: Smartphone-Based Accurate pH Sensing Using Electrospun Halochromic Nanofibers

  • Suryasnata Tripathy
  • Manne Shanmukh Reddy
  • Siva Rama Krishna Vanjari
  • Soumya Jana
  • Shiv Govind SinghEmail author


Development of an economical miniaturized platform for monitoring inherent biophysical properties of milk is imperative for tamper-proof milk adulteration detection. Towards this, herein, we demonstrate synthesis and evaluation of a paper-based scalable pH sensor derived from electrospun halochromic nanofibers. The sensor manifests into three unique color-signatures corresponding to pure (6.6 ≤ pH ≤ 6.9), acidic (pH < 6.6), and basic (pH > 6.9) milk samples, enabling a colorimetric detection mechanism. In a practical prototype, color transitions on the sensor strips are captured using smartphone camera and subsequently assigned to one of the three pH ranges using an image-based classifier. Specifically, we implemented three well-known machine learning algorithms and compared their classification performances. For a standard training-to-test ratio of 80:20, support vector machines achieved nearly perfect classification with average accuracy of 99.71%.


pH sensor Nanofibers Milk adulteration detection Electrospinning Support vector machines Monte Carlo cross validation 



A part of the reported work (characterization) was carried out at the Nanofabrication facility, Indian Institute of Technology Bombay under the Indian Nanoelectronics Users Program which is sponsored by Department of Electronics and Information Technology (DeitY), Ministry of Communications and Information Technology, the Government of India. Manne Shanmukh Reddy would like to thank the Ministry of Electronics and Information Technology (MeitY), the Government of India, for providing fellowship grant under Visvesvaraya PhD Scheme for Electronics and IT.

Compliance with Ethical Standards

Conflict of Interest

Suryasnata Tripathy declares that he has no conflict of interest. Manne Shanmukh Reddy declares that he has no conflict of interest. Siva Rama Krishna Vanjari declares that he has no conflict of interest. Soumya Jana declares that he has no conflict of interest. Shiv Govind Singh declares that he has no conflict of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed Consent

Informed consent is not applicable in this study.


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© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Electrical EngineeringIndian Institute of Technology HyderabadTelanganaIndia

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