Formaldehyde is a toxic volatile organic compound (VOC) found in building materials, furniture, and industrial emissions. Even at low concentrations, it can cause health issues ranging from respiratory irritation to cancer.
Indoor exposure often results from off-gassing by products such as insulation, furniture, and cleaning agents.2
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Given its risks, regulatory bodies have imposed strict exposure limits. For example, the World Health Organization recommends that indoor concentrations not exceed 0.1 mg/m3 (about 0.08 ppm) over a 30-minute period.2
The International Agency for Research on Cancer (IARC) has classified formaldehyde as “carcinogenic to humans (Group 1),” linking it to nasopharyngeal cancer and leukemia. While evidence for sinonasal cancer remains limited, animal studies have repeatedly shown increased nasal cancer rates in rodents exposed to high levels.4
Traditional detection methods like spectrophotometry and chromatography are precise but often too bulky and expensive for real-time monitoring. Nanosensors, built from materials at the atomic and molecular scale, offer a practical alternative.
These devices are highly sensitive and selective, many operate at room temperature, and they’re compact enough for on-site use. Materials such as metal oxide nanoparticles, carbon-based nanomaterials, and hybrid nanocomposites are commonly used to detect formaldehyde in homes, workplaces, and industrial settings.3
Why is it Important to Detect Volatile Organic Compounds (VOCs)?
Metal Oxide Nanoparticle-Based Nanosensors
Metal oxide semiconductors (MOS) such as tin oxide (SnO2), titanium dioxide (TiO2), and cobalt oxide (Co3O4) are widely used in gas sensing due to their sensitivity and stability. When engineered at the nanoscale, these materials gain a much larger surface area, which enhances their interaction with gas molecules.3
In one study, A. Nasriddinov et al. reported that TiO2@SnO2 nanocomposites could detect formaldehyde concentrations as low as 0.06 ppm. Sensor performance improved further under UV light, thanks to n–n heterojunctions at the TiO2/SnO2 interface that facilitated charge transfer.5
S. Bai et al. developed another promising design: Co₃O₄ hollow spheres with a 3D hierarchical structure. These nanosensors operate effectively at room temperature. Their hollow architecture provides a high surface area and numerous active sites for gas adsorption, resulting in fast response times and high sensitivity.6
Carbon-Based Nanomaterial Nanosensors
Carbon nanomaterials, including carbon nanotubes (CNTs), graphene, and their derivatives, possess exceptional electrical, mechanical, and chemical properties, making them ideal for sensing applications.
In one study, A. Kashyap et al. developed a cost-effective formaldehyde sensor using a reduced graphene oxide–tin oxide (rGO–SnO2) composite that operates at room temperature. The incorporation of SnO2 nanoparticles provided additional active sites for formaldehyde adsorption, while rGO supported efficient electron transport.
The sensor achieved a theoretical detection limit of just 33 parts per billion (ppb) and maintained good stability for up to 120 days. It also showed practical use in detecting formaldehyde in adulterated fish samples, highlighting its potential for VOC monitoring and food safety.7
Chen et al. proposed another innovative design using 3D-printed aerogel filaments made from quantum dots and graphene. These sensors demonstrated real-time, noise-resistant formaldehyde detection at room temperature, with detection limits as low as 8.02 ppb. They also consume very little power (around 130 µW).
The integration of intelligent algorithms further enhanced their accuracy and stability under varying environmental conditions.8
Hybrid Nanocomposite Nanosensors
Hybrid nanocomposites combine different materials to take advantage of each one's strengths, often resulting in better sensor performance.
One example is a sensor made from zeolitic imidazolate framework-8 (ZIF-8) and multiwalled carbon nanotubes (MWCNTs). ZIF-8 provides a high surface area, while MWCNTs offer good electrical conductivity. Together, they enable fast and sensitive detection of formaldehyde at room temperature.9
Some researchers are also using greener methods. In one study, Kundu et al. used mango tree leaf extracts to create magnetite nanoparticles. These were used to make a low-cost, environmentally friendly sensor that could detect formaldehyde in fruits and vegetables.10
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Applications in Indoor Air Quality and Industrial Safety
Nanosensors offer clear advantages for monitoring formaldehyde in both home and industrial settings.
Indoor Air Quality
Small and portable nanosensors can be built into smart home systems to track indoor formaldehyde levels in real time. This helps maintain a healthy living environment by providing early warnings.11
A study by Ramaiyan and Mukundan highlighted recent progress in nanosensors for air quality, especially for detecting VOCs at low levels. They point to advances in chemiresistive and mixed-potential sensors using materials like graphene and ZnO nanowires. These sensors have shown strong results in lab tests and field trials, with potential for use in smart homes and wearable devices.12
Industrial Safety
In workplaces where formaldehyde is produced or used, nanosensors can act as early warning tools by quickly detecting leaks or unsafe concentrations.11
One example comes from Li et al., who developed a voltammetric sensor using NiCoMnO4–rGO nanocomposites. It was designed to detect bisphenol AP (BPAP) in industrial wastewater. The sensor could measure concentrations as low as 2 nM and performed well when tested with real wastewater samples using the standard addition method.13
Challenges and What’s Next for Nanosensor Technology
While nanosensors show strong promise for detecting formaldehyde, several challenges remain.
A key issue is selectivity—making sure the sensor responds specifically to formaldehyde and not to other VOCs. Researchers are working to improve this by modifying nanomaterials and designing more selective sensing components.1
Long-term stability is another concern. Sensors need to stay reliable under changing environmental conditions, such as shifts in humidity or temperature. Scalability is also a challenge. Producing nanosensors in large quantities with consistent performance is essential for practical, widespread use.1
Future research will likely focus on addressing these issues by developing sensors that can detect multiple pollutants, creating wearable formats, and using machine learning to improve how sensor data is processed and interpreted.1
Ongoing progress in nanomaterials and sensor design will continue to broaden how and where nanosensors can be used to reduce formaldehyde-related health risks. If you’re interested in how these technologies are being applied in other areas, visit:
References and Further Reading
1. Jalal, A. H.; Alam, F.; Roychoudhury, S.; Umasankar, Y.; Pala, N.; Bhansali, S. (2018). Prospects and Challenges of Volatile Organic Compound Sensors in Human Healthcare. Acs Sensors. https://pubs.acs.org/doi/full/10.1021/acssensors.8b00400
2. Nielsen, G. D.; et al. (2017) Formaldehyde Indoor Air Quality Guideline for Cancer Risk Assessment. Archives of toxicology. https://pmc.ncbi.nlm.nih.gov/articles/PMC5225186/#CR54
3. Vyas, T.; Parsai, K.; Dhingra, I.; Joshi, A. (2023). Nanosensors for Detection of Volatile Organic Compounds. Advances in Smart Nanomaterials and Their Applications, Elsevier: 2023; pp 273-296. https://www.sciencedirect.com/science/article/abs/pii/B9780323995467000069
4. Protano, C.; Buomprisco, G.; Cammalleri, V.; Pocino, R. N.; Marotta, D.; Simonazzi, S.; Cardoni, F.; Petyx, M.; Iavicoli, S.; Vitali, M. (2021). The Carcinogenic Effects of Formaldehyde Occupational Exposure: A Systematic Review. Cancers. https://www.mdpi.com/2072-6694/14/1/165
5. Nasriddinov, A.; Rumyantseva, M.; Marikutsa, A.; Gaskov, A.; Lee, J.-H.; Kim, J.-H.; Kim, J.-Y.; Kim, S. S.; Kim, H. W. (2019). Sub-Ppm Formaldehyde Detection by N-N Tio2@Sno2 Nanocomposites. Sensors. https://www.mdpi.com/1424-8220/19/14/3182
6. Bai, S.; Guo, J.; Shu, X.; Xiang, X.; Luo, R.; Li, D.; Chen, A.; Liu, C. C. (2017). Surface Functionalization of Co3o4 Hollow Spheres with Zno Nanoparticles for Modulating Sensing Properties of Formaldehyde. Sensors and Actuators B: Chemical. https://www.sciencedirect.com/science/article/pii/S0925400517301090
7. Kashyap, A.; Chakraborty, B.; Siddiqui, M. S.; Tyagi, H.; Kalita, H. (2023). Selective and Sensitive Detection of Formaldehyde at Room Temperature by Tin Oxide Nanoparticles/Reduced Graphene Oxide Composite. ACS Applied Nano Materials. https://pubs.acs.org/doi/full/10.1021/acsanm.3c01183
8. Chen, Z.; Zhou, B.; Xiao, M.; Bhowmick, T.; Karthick Kannan, P.; Occhipinti, L. G.; Gardner, J. W.; Hasan, T. (2024). Real-Time, Noise and Drift Resilient Formaldehyde Sensing at Room Temperature with Aerogel Filaments. Science Advances. https://www.science.org/doi/10.1126/sciadv.adk6856
9. Homayoonnia, S.; Kim, S. (2023). Zif-8/Mwcnt-Nanocomposite Based-Resistive Sensor for Highly Selective Detection of Acetone in Parts-Per-Billion: Potential Noninvasive Diagnosis of Diabetes. Sensors and Actuators B: Chemical. https://www.sciencedirect.com/science/article/pii/S0925400523009127?via%3Dihub
10. Kundu, M.; Krishnan, P.; Prasad, S.; Chawla, G. (2024). Green Nanosensor for Precise Detection of Formaldehyde in Fruits and Vegetables Extract. Food Chemistry. https://www.sciencedirect.com/science/article/pii/S0308814624001687
11. Godja, N.-C.; Munteanu, F.-D. (2024). Hybrid Nanomaterials: A Brief Overview of Versatile Solutions for Sensor Technology in Healthcare and Environmental Applications. Biosensors. https://www.mdpi.com/2079-6374/14/2/67
12. Ramaiyan, K. P.; Mukundan, R. (2019). Electrochemical Sensors for Air Quality Monitoring. The Electrochemical Society Interface. https://iopscience.iop.org/article/10.1149/2.F08193IF/meta
13. Li, H.; Guo, S.; Wang, L. (2021). Voltammetric Sensor Detection of Bisphenol Ap in Industrial Wastewater. International Journal of Environmental Analytical Chemistry. https://www.tandfonline.com/doi/full/10.1080/03067319.2019.1678605
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