1. A method for nucleic acid sequencing, comprising: providing an array of chemical sensors, the chemical sensors comprising field-effect transistors having floating gates coupled to sensitive areas arranged along a substantially planar surface, a receptor covalently coupled to the sensitive areas, the receptor to reversibly bind a phosphate; delivering template nucleic acids proximate to the sensitive areas of the sensors; introducing a nucleotide, the nucleotide incorporating into a nucleic acid strand complementary to the template nucleic acid and releasing the phosphate, the phosphate reversibly binding to the receptor; and detecting output signals from the chemical sensors indicating incorporation of the introduced nucleotide into the template nucleic acids, the output signal responsive to the reversible binding of the phosphate to the receptor.