Highpoints of carbon nanotube nanocomposite sensors—A review

•Design and potential of inimitable hollow cylindrical carbon nanotube nanostructures for high-tech sensors.•Sensing efficiency of multifunctional carbon nanotube nanocomposites with conducting matrices like poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, and polyaniline and thermoplastics like polyamide, polyurethane, etc.•Carbon nanotube percolation network for competent electron or charge transportation and development of interfacial interactions.•Employment of carbon nanotube nanocomposites for high-tech gas sensors, strain sensors, and biosensors.•Sensitivity, selectivity, detection limit, reproducibility, and responsiveness of carbon nanotube sensors towards analytes (gasses/ions, biomolecules, or motion).