Organic Molecule Based Sensor for Aldehyde Detection

Abstract

Abstract. Aldehydes are used in food and beverage industries, production of resins, soap and perfume industries. When used in excess quantity or found in products in undesired quantity this is a threat to humans. Hence it becomes very important to detect these VOCs even at lower concentration. The other sources of aldehyde are polluted air and water. Exposure to aldehyde can cause gene mutation and cancer. Conductometric sensors with metal oxide semiconductors as sensing films, cataluminesence based sensors, quartz crystal microbalance sensors, analytical methods such as HPLC have been used for the detection of aldehydes. These are sophisticated techniques require skilled staff to perform the tests. Chemiresistor is a simple method of fabrication of conductometric sensor. In this method the sensing layer is a film cast between two electrodes deposited on an insulating substrate. The response of the sensor to various analytes is monitored by recording the changes taking place in the sensing element. Organic molecule based sensors are low cost and operate at room temperature. Selectivity of the sensors to a particular analyte is an issue in sensors. An analyte molecule can interact with the various binding sites on a molecule. A molecule has to be designed and synthesized to be selective to a particular analyte of interest. This can be achieved by selecting a molecule which has a functional group that interacts with the analyte molecule. The mechanism of interaction of the analyte with the sensing molecule can be understood by doing molecular simulations. Molecular modelling allows monitoring the interaction of the analyte and sensing molecule. Here an example of organic molecule based sensor for selective interaction with aldehydes is illustrated.The organic molecule ophenylenediamine blended with carbon black as sensing element of the chemiresistor to decrease the resistance. Molecular modelling can be used to understand the interaction between aldehyde and o-phenylenediamine molecule.

Phosphonic Acid Modified ZnO Nanowire Sensors: Directing Reaction Pathway of Volatile Carbonyl Compounds

“…Aliphatic aldehydes are most important chemical groups in the field of biosensing because of their ubiquities and informativities. , For example, nonanal, an aliphatic aldehyde with a carbon number of 9, can act as a disease marker because it is specifically found in the breath of lung cancer patients. , Therefore, the gas-phase aldehyde detection has received growing attention in the recent years by utilizing metal oxide semiconductor (MOS)-based electrical sensors. , On the other hand, the abundant reactivity of aliphatic aldehydes is often problematic for the MOS sensor applications. For instance, metal oxide surfaces are known to promote “aldol condensation” of aldehydes to yield much heavier products, − which can inhibit sensor recoveries.…”

Evaluation of Three Peptide Immobilization Techniques on a QCM Surface Related to Acetaldehyde Responses in the Gas Phase

“…Up to date, several technologies were considered for their detection by using metal oxides [ 42 ] or QCM coated with polymers [ 43 ] such as MIP [ 44 ]. As compared to various commercial aldehyde sensors’ sensitivity (~5 ppm), the peptide-based QCM sensors have shown a better sensitivity [ 11 ] and comparable to that of a sensor developed by Imashi et al [ 45 ] and Giberti et al [ 46 ]. A sensor with the MIP film, with a similar sensitivity for aldehyde was also developed by Debliquy et al [ 44 ].…”

“…Selectivity of a sensor depends on the sensing material used. Generally, molecules implemented on sensor’s surface need to be designed and synthesized in such way as to achieve recognition site specific to particular analyte [ 11 ]. Owing to the ease of peptides synthesis, through modification the side chains of amino acids, the affinity for specific odorants can easily be increased.…”

A Cataluminescence Sensor Based on NiO Nanoparticles for Sensitive Detection of Acetaldehyde

“…Acetaldehyde is a major environmental pollutant found associated with many human activities, for instance, cigarette smoke, vehicle exhaust, solid biological wastes, and open burning of gas, oil and coal [11,12]. The risk of asthma and cancer will be increased, for people with long-term exposure to acetaldehyde, even at low concentration [13].…”