Rapid Liquid Recognition and Quality Inspection with Graphene Test Papers

Abstract

essential for meeting the future needs in various aspects of liquid monitoring.Conventional technologies of liquid sensing includes chemical analysis, spectroscopic analysis, liquid parameter analysis, bioelectronic/electronic tongue and chemiresistor. Chemical analysis method has a long history, e.g., titrimetry analysis and colorimetric analysis. As for it is dependent on a specific chemical reaction, it is targeted detection and could achieve qualitative/quantitative analysis. [6] Spectroscopic analysis instruments, such as X-ray, photonic-crystal fibers, surface-enhanced Raman spectroscopy, could realize accurate chemical analysis. [7][8][9][10][11] However, chemical and spectrum analysis method requires expensive laboratory equipment and highly qualified personnel, which are not suitable for real-time on-the-spot detection. Liquid parameter analyzers, such as surface tension apparatus or viscometer, are accurate, fast, and portable, [12] but its application was limited to the identification of organic solvents or specific liquids.Electronic tongue consisting of an array of nonselective chemical sensors could analyze simple or complex solutions quantitatively or qualitatively. [13][14][15] Electronic tongues based on different principles have been proposed, including voltammetric, potentiometric, impedimetric, optical, and enzymatic sensors. [14,[16][17][18][19][20] Owing to structural limitations, existing electronic tongues could hardly be embedded into flexible, portable, and wearable devices. Bioelectronic tongues obtain complex chemical information in biomaterial platform, including nanovesicles or living cells. [21][22][23] With high-performance odorant discriminatory ability in mixtures, bioelectronic tongues are suitable for portable rapid detection equipment, but the preparation cost is relatively high, and the testing conditions are complicated. Chemiresistor could change electrical resistance in the presence of chemical, which has widely applications in gas sensor. [24] Chemiresistor is characterized by high detection accuracy, relatively simple detection conditions, low manufacturing cost. However, in chemiresistor-based liquid-sensing system, the mechanism is based on the swelling of polymer substrate, so the detected liquid only limited to organic solvents. [25][26][27] As for its relatively simple structure, chemiresistor could be easily integrated as part of a flexible functional circuit. With designed sensing materials, electrical tongue based on chemiresistor has great potential to offer a unique and compelling capability for classification and detection of tested liquid.Electronic tongue is widely applied in liquid sensing for applications in various fields, such as environmental monitoring, healthcare, and food quality test. A rapid and simple liquid-sensing method can greatly facilitate the routine quality tests of liquids. Nanomaterials can help miniaturize sensing devices. In this work, a broad-spectrum liquid-sensing system is developed for rapid liquid recognition based on disposable...

Multifunctional two-dimensional glassy graphene devices for vis-NIR photodetection and volatile organic compound sensing

“…4b) were extracted. Although the response of the FGD was comparable to the graphene one, the initial response of the FGD was noticeably larger than that of graphene at V bias = 0.01 V. Moreover, the sensitivity of the FGD was comparable or even superior to the reported liquid acetone sensors based on reduced GO (ΔR/R 0 =~45% for bilayer), graphene/cellulose nanocomposite (ΔR/R 0 = 2%-10%), and Co 3 O 4 -doped ZnO (ΔI/I 0 =~20%) [68][69][70]. R 0 and R represent the channel resistance before and after VOC liquids in contact with channels, respectively, and ΔR is the difference of R and R 0 .…”

A Highly Stable Diketopyrrolopyrrole (DPP) Polymer for Chemiresistive Sensors

“…First, it is known that the electrical current of a chemiresistor may change in response to the analyte that has a different chemical nature from that of the channel polymer material. [ 71–73 ] Therefore, the direction and magnitude of the current change may vary with different liquids. For example, the liquids in the first row (chloroform, hexane, diethyl ether, etc.)…”

Structure–Function Relationships of Nanocarbon/Polymer Composites for Chemiresistive Sensing: A Review

“…However, at room temperature, the response to humidity was much higher, which could compromise sensor reliability. A flexible and portable chemiresistor-based G-cellulose nanocomposite test paper (NCTP) comprising a G-lamellar membrane on a polymer substrate was introduced by Jiang’s team for rapid liquid recognition [ 93 ]. In the proposed sensing platform, the liquid droplet would penetrate into NCTP, impact the contact state and the carrier density of the G-sheet, and alter the total resistance.…”