ABSTRACT Valsartan and Losartan are two angiotensin II receptor blocker drugs used to treat heart failure and high blood pressure. A straightforward and disposable hollow fibre-solid phase microextraction device was developed to extract these drugs from real water and urine samples. A green sorbent was synthesised by functionalised MWCNTs with chitosan through a chemical route method. Besides, a polyoxometalate (Ni-CoWO4 nanoparticles) was prepared as a modifier using the hydrothermal procedure. Using the sol-gel strategy, the sorbent and modifier were reinforced in the hollow fibre pores and lumen. The approach leads to an increase in the sorbent coating stability on/in hollow fibre. The influential factors were optimised with an experimental design, indicating that pH, extraction time, and desorption time significantly affect the Valsartan and Losartan extraction. The linearity of the method to determine Valsartan and Losartan was 3.4–1850 and 3.1–1800 ng mL−1, with R squared of 0.9929 and 0.9947, respectively. The detection and quantification limits were lower than 0.9 ng mL−1 and 3.4 ng mL−1, respectively. The pre-concentration factors for determining Valsartan and Losartan with a concentration of 20 ng mL−1 were 654.2 and 546.3, respectively. The intra-day and inter-day RSDs were lower than 3.11% and 3.87% for measuring Valsartan and Losartan. The recoveries and RSDs for analysing spiked eal water and urine samples were between 91.8–97.8% and 3.16–4.10%, respectively.