Laboratory for Analytical Chemistry

Citterio Laboratory


Innovation of Chemical Sensors

Keio University

Faculty of Science and Technology

Department of Applied Chemistry

Low-Cost Analytical Devices for Healthcare and Environment


Our research group has more than 10 years of experience in the development of (microfluidic) paper-based analytical devices, (µ)PADs. These are analytical assay devices intended for general end users, allowing to monitor important clinical or environmental analytes at the point of need. The philosophy behind (µ)PADs is to provide low-cost, simple to use, but still reliable analytical devices applicable for diagnostic or environmental analysis in low-resource settings, such as those encountered in developing countries or in home-healthcare situations, for example.


In this context, paper plays an important role as a low-cost chemically and physically functional material. A particular strength of our group lies in the experience with inkjet deposition of a large variety of chemically functional materials (proteins, indicators, polymers, metal nanoparticles, etc.). The combination of modern drop-on-demand inkjet printing with paper substrates allows the precisely controlled contactless deposition of picoliter-sized liquid droplets, contributing to the reproducible fabrication of paper-based analytical devices. Using equipment as simple as office desktop inkjet printers, we have realized colorimetric (µ)PADs for clinical tear protein analysis, drug components, urinary compounds or metal cations in environmental water samples, among others. The same simple printing technologies have also resulted in the realization of text-based semi-quantitative signaling approaches, where users can directly read the target analyte concentration from the device in the form of a number or a symbol. Such approaches could only be realized by means of precise, but flexible reagent deposition through inkjet printing.


Our team has also been active in implementing the technologies of ion-selective electrodes (ISEs) and ion-selective optodes (ISOs) into very simple to operate single-use (µ)PADs. Their use only requires the application of the sample liquid, eliminating all sample preparation and sensor conditioning steps.


In collaboration with industrial partners, some of our developed devices are currently undergoing further development towards commercialization.


For specific information, please refer to our list of publications.



Citterio Laboratory 2022

Last update: March 08, 2022