8. Share-based payments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Payments Details
Nonemployee common stock	$ 602,507	$ 631,550
Nonemployee warrants - fully vested upon issuance	6,981	7,204,573
Nonemployee warrants - service and performance conditions	$ 52,056	264,919
Employee stock options - fully vested upon grant		7,950,000
Employee stock options - market price-based	$ 1,308,000	$ 2,321,000
Legal settlement - replacement warrants	1,764,450
Total share-based expense charged against income	$ 3,733,994	$ 18,372,042
Impact on net loss per common share: Basic and diluted	$ (0.06)	$ (0.32)