Browsing by Author "Chen, Jian-Nan"

Now showing 1 - 2 of 2

Modulated gas sensor based on vertical organic diode with blended channel for ppb-regime detection
(2016-07)
Chuang, Ming-Yen
;
Chen, Jian-Nan
;
Zan, Hsiao-Wen
;
Lu, Chia-Jung
;
Meng, Hsin-Fei
We demonstrate an extremely sensitive ammonia gas sensor based on vertical organic diode to exhibit a 1 ppb detection limit. Using phenyl-C61-butyric acid methyl ester (PCBM) as the sensing layer, the nano porous structure enlarges the surface to volume ratio and hence realizes the ppb-regime sensitivity. The proposed vertical nano-junction (VNJ) organic diode is then investigated by changing the semiconducting materials (i.e. sensing material). In addition to a pure n-type or p-type sensing material, the blend of n/p organic semiconductor (PCBM/P3HT) is used to react with gas. Changing the n/p blending ratio from 0 to 100% delivers a tunable gas response to ammonia and nitric oxide, hence demonstrating a sensing map concept with good selectivity. (C) 2016 Elsevier B.V. All rights reserved.
One-Minute Fish Freshness Evaluation by Testing the Volatile Amine Gas with an Ultrasensitive Porous-Electrode-Capped Organic Gas Sensor System
(2017-04-01)
Chang, Liang-Yu
;
Chuang, Ming-Yen
;
Zan, Hsiao-Wen
;
Meng, Hsin-Fei
;
Lu, Chia-Jung
In this work, we successfully demonstrate a fast method to determine the fish freshness by using a sensing system containing an ultrasensitive amine gas sensor to detect the volatile amine gas from the raw fish meat. When traditional titration method takes 4 h and complicated steps to test the total volatile basic nitrogen (TVB-N) as a worldwide standard for fish freshness, our sensor takes 1 min to deliver an electrical sensing response that is highly correlated with the TVB-N value. When detecting a fresh fish with a TVB-N as 18 mg/100 g, the sensor delivers an effective ammonia concentration as 100 ppb. For TVB-N as 28-35 mg/100 g, a well-accepted freshness limit, the effective ammonia concentration is as 200-300 ppb. The ppb-regime sensitivity of the sensor and the humidity control in the sensing system are the keys to realizing fast and accurate detection. It is expected that the results in this report enable the development of on-site freshness detection and real-time monitoring in a fish factory.