Silicon seems promising when it comes to being the basis of life, but when the topic is researched futher. Carbon, when it is oxidized during the respiratory process, it becomes the gas carbon didoxide which allows it be released easily out of a body. When Silicone is oxidised, it has a reaction in which the product of it is a solid. This happens when it becomes oxidsed as the silicon dioxied atoms form bonds with each other. each silicon atom is then surrounded by four oxygen atoms thus causing a respiratory problem as the body will not get enough oxygen as some of it connects to the silicone.
Life forms must also be able to collect and store energy from thier environment. The basic form of energy the human body needs are carbo hydrates. Carbohydrates are when carbon atoms are linked by single bonds into a chain. To obobtain energy, the carbohydrate then needs to be oxidised to release energy through a series of steps using enzymes. the enzymes catalyse specific reations caused by their shape and hanedeness. If this was the case for silicone, when being oxidised, it would cause many problems similar to those u of the respiratory system.
Although these facts prove that current life would not be able to survive using silicon as their primary basis of life, but there is some evidence that it may have had parts to play in the original life on earth. Little evidence supports this but the fact that the first prebiotic compounds formed in a "Primordial soup" on a surface of silca which had a certain handedness of the carbon compounds now found in life forms today.