Chemical Sensors

Vol. 21, No. 4(2005)



荒川 剛

近畿大学 産業理工学部 環境化学科・教授

Look Back on 30 Years for Study of Chemical Sensors

Tsuyoshi ARAKAWA

Kinki Univ.



庄司 英一

福井大学工学部 知能システム工学科・助教授
〒910-8507 福井県福井市文京3-9-1

Development of Active Sensing Elements
with Poly(anikine boronic acid):
A Nonenzymatic Glucose Sensor
and A New Precursor Route to Substituted Polyaniline

Eiichi SHOJI

Department of Human and Al Systems,University of Fukui
3-9-1 Bunkyo,Fukui 910-8507, Japan

       A new strategy that exploits inductive and resonant effect of reactive substituents on the pka of polyaniline to produce active sensing elements has been discussed. Boronic acid-based sensors provide attractive alternative enzyme-based sensors the complexation is a reversible, equilibrium-based reaction (i.e.,the analyte is not consumed).
The alternative approach is the electrochemical transduction induced of the boronic acid groups in PABA.
In addition to sensing applications, boronic acids provide versatile chemical reactivity that allows it to be converted
into a wide range of substituent groups. Examples include, but not limited to, the conversion to hydroxyl, halogen, and nitro groups under mild conditions. In these particular examples, a boron activation/electrophilic displacement mechanism resulting in ipso-substitution is proposed.
The novel precursor route from PABA to other polyaniline derivatives, in fact, allows the production of polyaniline derivatives that have not been made previously due to complicating side reactions.
This new electrochemical method has the capability to manipulate the reaction conditions as well as to allow chemical reaction control. With a careful control of electrochemical and reaction conditions, the production of poly (hydroxy aniline) and poly (haloaniline) s was successful. These sensing and material strategies using PABA will be a breakthrough for developing new elements.


石原 伸介

京都電子工業株式会社 研究開発本部・新規製品マーケティング担当
〒601-8371 京都市南区吉祥院新田二の段 56-2

Aspects for “SENSORS”as Equivalent Point Detectors in Titration
-The Streaming Potential Sensor to Detect Endpoint for Titration-


Marketing New Products,Division of Research & Development Kyoto Electronics Msnufacturing Co., Ltd.
56-2 Shinden Ninodancho, Kissyoin Minamiku, Kyoto 601-8371, Japan

1) These could be many answers to the question, “What is CHEMICAL SENSOR?” Generally, we understand that it is the concentration of individual chemical materials directly responding to the sensor's signal.
In this case, sensors are required to feature harsh characteristics, such as high selectivity, high sensitivity, a wide range of linearity, and long term durability, etc. In another case, we consider sensors as only sub-tool to obtain information on concentration. In this report, taking an example of titration as one of the methods to obtain information on concentration, I will introduce “Streaming potential sensor” as one that can detect the endpoint for titration with higher sensitivity.

2) The Streaming Potential Sensor is, as described in the foregoing “Sensor” aspect, a specializad sensor for detecting an equivalent point in titration. That is, this sensor does not fit in the direct determination of the concentration of an objective chemical but is very sensitive in detecting the endpoint for titration.
Further, its principle of operation is much more different from the image of an ordinary electrode. Although the fields applicable for this sensor is limited because of its uniqueness compared with ordinary electrodes, new applications are expected from new perspectives.

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