Example of direct chemoreceptors are:
Chemoreceptor (Chemosensor) is a sensory receptor that transduces a chemical signal into an action potential. There are two main classes of chemosensor.
a) Direct:
Taste buds are direct chemoreceptors. Aqueous chemical compounds come into contact with chemoreceptors in the mouth such as taste buds on the tongue and trigger responses.
b) Distant: 
Olfactory receptor neurons in the olfactory system. The main olfactory epithelium (MOE) and the Vomeronasal organ (VNO) detects odorants and pheromones respectively.
Olfactory receptor neuron.
Taste buds.
Vomeronasal organ.
All of the above.