Republished from the Graduate Student Forum.
Chemistry PhD student Sadik Antwi-Boampong describes how he used the Graduate Alumni Research Award to assist him in his research.
Formaldehyde is a dangerous chemical that is found in many common materials. The Graduate Alumni Research Award supported my group’s work in developing a sensor that can detect the presence of formaldehyde in real time so that people can be warned about immediate exposure.
Formaldehyde is a ubiquitous carcinogen that leaches from construction materials and household appliances, and abounds in cigarette aerosol. Systemic exposure to formaldehyde causes myeloid leukemia, as well as cancers of the lungs, throat, and mouth. It has been reported that exposure to formaldehyde concentrations as low as 1 part-per-million has debilitating health effects. Current formaldehyde sensors are expensive, insensitive, and do not detect in real time. The goal of our project is to produce a procedure for detecting formaldehyde that has significantly higher sensitivity and is relatively inexpensive to be used for a variety of commercial applications.
In the first phase of the project, we developed a prototype using a patterned silicon substrate coated with the sensing layer, which is a conductive composite film composed of long interconnected molecules, polyaniline and polyethylenimine. The sensor sensitively detects formaldehyde vapor and also rapidly responds to formaldehyde. An image of the composite film is included here.
In the final phase of the project, we were interested in quantifying the amount of formaldehyde the sensor adsorbs following exposure to a known concentration of formaldehyde. However, formaldehyde is difficult to quantify using standard laboratory methods like gas chromatography (GC). This led us to examine a novel, simple, and yet robust quantification method for formaldehyde that requires a specialty technique called solid-phase microextraction (SPME) with On-Fiber Derivatization. With this technique, the formaldehyde molecule is reacted to form a stable compound that is easily quantifiable by gas chromatography.
Thanks to the Graduate Alumni Research Award, we were able to apply the SPME-fiber technique to answer the critical question: How much formaldehyde really binds to the sensor when it is exposed to a known concentration of formaldehyde vapor? Specifically, the award was used to purchase the materials for the GC technique. This powerful technique enhanced the GC quantification of our sensor and, beyond our work on formaldehyde, can also be applied to analyze the other target molecules we study in our group.
by Sadik Antwi-Boampong