Quantum dots (QDs) have attracted increasing attention due to their unique physical and chemical properties. This article introduces recent advances in using QDs' photoluminescence (PL) for in vitro and intracellular sensing analytes, in particular ions, and biomolecules from the last 3 years. Different sensing strategies are demonstrated and compared for increasing the detecting/sensing selectivity. The perspectives for in vitro and intracellular sensing based on QDs' PL are also discussed.