Nafion® Coated Electropolymerised Flavanone‐Based pH Sensor

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

Download Full-text

CMOS-Compatible Ex-situ Incorporated Junctionless Enhancement-mode Thin Polysilicon Film FET pH Sensor

IEEE Transactions on Device and Materials Reliability ◽

10.1109/tdmr.2020.3041190 ◽

2020 ◽

pp. 1-1

Author(s):

Jaydeep Singh Parmar ◽

Chitrakant Sahu

Keyword(s):

Ph Sensor ◽

Ex Situ ◽

Polysilicon Film ◽

Enhancement Mode ◽

Cmos Compatible

Download Full-text

Ex-Vivo Measurement of the pH in Aqueous Humor Samples by a Tapered Fiber-Optic Sensor

Sensors ◽

10.3390/s21155075 ◽

2021 ◽

Vol 21 (15) ◽

pp. 5075

Author(s):

Ondřej Podrazký ◽

Jan Mrázek ◽

Jana Proboštová ◽

Soňa Vytykáčová ◽

Ivan Kašík ◽

...

Keyword(s):

Cataract Surgery ◽

Aqueous Humor ◽

Fiber Optic ◽

Ex Vivo ◽

Sol Gel ◽

Ph Sensor ◽

Fiber Optic Sensor ◽

Optic Sensor ◽

Tapered Optical Fiber ◽

Practical Demonstration

A practical demonstration of pH measurement in real biological samples with an in-house developed fiber-optic pH sensor system is presented. The sensor uses 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) fluorescent dye as the opto-chemical transducer. The dye is immobilized in a hybrid sol-gel matrix at the tip of a tapered optical fiber. We used 405 nm and 450 nm laser diodes for the dye excitation and a photomultiplier tube as a detector. The sensor was used for the measurement of pH in human aqueous humor samples during cataract surgery. Two groups of patients were tested, one underwent conventional phacoemulsification removal of the lens while the other was subjected to femtosecond laser assisted cataract surgery (FLACS). The precision of the measurement was ±0.04 pH units. The average pH of the aqueous humor of patients subjected to FLACS and those subjected to phacoemulsification were 7.24 ± 0.17 and 7.31 ± 0.20 respectively.

Download Full-text