Engineering 1T-MoS₂ core-shells unified with nitrogen-rich amorphous carbon nanotube for ratiometric low-level detection of nitroquinoline

Nitroquinolines are an important toxic element in ecosystems and have great significance for monitoring the environmental system with appropriate tools for safety assessments. In this work, we developed a sensitive method for accurate and low-level detection of 5-nitroquinoline (5-NQ) using 1T-molybdenum disulfide core shells unified with nitrogen-rich amorphous carbon nanotube (1T-MoS₂/NCNT). The 1T-MoS₂/NCNT core-shells composite is prepared using a hydrothermal method to fabricate a ratiometric low-level detection of a 5-NQ sensor. The screen-printed carbon electrode (SPCE) modified with 1T-MoS₂/NCNT reveals superior electrochemical performance for the detection of 5-NQ with a wide dual linear range of 0.03–258.58 µM and 274.91–604.25 µM, low-level detection limit (LOD) of 0.0089 µM, and a higher sensitivity of 1.83 µA µM⁻¹ cm⁻² due to its higher electrochemical active surface area, superior conductivity, and excellent stability. The π-delocalized electrons in 5-NQ facilitate the rapid electron transfer at the electrode-electrolyte interface, allowing easy conjugation with 1T-MoS₂/NCNT. The operational stability of the sensor retains 98.7 % after 40 consecutive cycles. In addition, the achieved recovery rates are 96.80–99.76 % and 97.93–99.75 % for 5-NQ detection in various soils and water samples, signifying its feasibility for real-time industrial waste monitoring.