# Air Pollution Monitoring with Nanoscaled Materials in Chemoresistive Gas Sensors

## TL;DR

This paper reviews recent advances in using nanoscaled materials for chemoresistive gas sensors to monitor air pollutants and their integration into environmental monitoring devices.

## Contribution

The paper provides a critical review of recent progress in nanostructured chemoresistive gas sensors for air pollution monitoring.

## Key findings

- Nanostructured and porous materials improve gas sensor performance for detecting pollutants.
- Engineering strategies like surface functionalization enhance pollutant adsorption and sensor signals.
- Integration into consumer electronics and wearables is a promising direction for real-world applications.

## Abstract

Air pollution is a pressing global concern due to its
negative
effects on human health and our ecosystem. For instance, pollutants,
including particulate matter, volatile organic compounds, nitrogen-
and sulfur-based gases, and ozone, are known to increase the incidence
rates of respiratory, cardiovascular, and various cancer types, among
others. Comprehensive monitoring of key gaseous pollutants is, therefore,
critical to enforce adherence to regulatory limits or to control personal
exposure. In this review, we analyze the progress on nanostructured
and porous chemoresistive gas sensors over the last five years and
critically compare their performance to air pollution guidelines.
We start with a discussion of the major outdoor and indoor pollutants,
describing their main sources and the associated health effects arising
from short- and long-term exposures to concentrations exceeding national
and regional limits. Thereafter, we describe the working mechanism
of chemoresistive gas sensors along with their key performance parameters,
followed by a literature survey of several nanoscaled porous materials
for such applications. We highlight different engineering strategies
focused on structural, morphological, and electronic control through
heterostructures, surface functionalization, and metal–organic
framework templates that tune air pollutant adsorption, catalytic
conversion on their surfaces, and sensor signal generation. Finally,
we briefly discuss the integration of these gas-sensing technologies
into functional devices to translate material and surface innovation
into environmental monitoring platforms for consumer electronics,
wearables, and smart-home solutions.