Low-cost air-quality (AQ) sensors, when integrated into Internet of Things (IoT) nodes, can provide dense spatiotemporal measurements at a fraction of the cost of conventional stations. This paper presents the design and deployment of a six-node, low-cost AQ monitoring network at the Queen Mary University of London Mile End Campus (QMUL Mile End). Each node samples every 30 s and measures temperature, relative humidity, VOC index, PM2.5/PM10, and raw surrogate signals (CO, NO2, O3) from low-cost gas sensors, suitable for trend analysis rather than absolute concentrations. Data are buffered in SQLite on-node and synchronised in batches to a local InfluxDB service. Outdoor nodes employ a robust “hanging basket” design using a thin, flat pass-through window cable that both supports and powers the node. The paper focuses on design and implementation; performance modelling, calibration and indoor–outdoor analyses are left for future work.