pH Sensors with Off-On-Off Mechanism

  • ChemPubSoc Europe Logo
  • Author: Joseph Unsay
  • Published Date: 23 January 2017
  • Source / Publisher: Chemistry – A European Journal/Wiley-VCH
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
thumbnail image: pH Sensors with Off-On-Off Mechanism

Related Societies

Electrochemical sensors are well-established and widely used for pH measurements. However, they still have some disadvantages, such as the need for frequent calibration and sensitivity to electrical interference. As an alternative, optical sensors use the reversible changes on spectroscopic properties of indicators induced by pH, which makes them ideal for field applications.

Victor N. Nemykin, University of Minnesota, Duluth, USA, and University of Manitoba, Winnipeg, Canada, Petr Zimcik and Veronika Novakova, Charles University, Prague, Czech Republic, and colleagues developed pH-sensitive red-emitting fluorescent probes based on tetrapyrazinoporphyrazines (TPyzPzs).

The researchers were able to tune the fluorescence intensity of TPyzPzs through the basicity of two nitrogen atoms, which act as "switches". The first switch is in the backbone of TPyzPzs and the second one is in the peripheral group. When both switches are "on", the high fluorescence intensity is high, and this state occurs only at a narrow pH range (pH 1–2.5). Below pH 1 and above pH 2.5, the system is considered "off". The team also showed that depending on the peripheral group, different "on/off" mechanisms could be exploited. The developed compounds show promise as possible candidates for fluorescence-based pH-sensor devices.


Article Views: 1910

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from, please contact us first for permission. more

CONNECT: on Facebook on Twitter on YouTube on LinkedIn Sign up for our free newsletter

A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH