| Basic and diluted net loss per share | 
|  |  | Three
    Months Ended March 31, |  |  | Six
    Months Ended March 31, |  |  
|  |  | 2014 |  |  | 2013 |  |  | 2014 |  |  | 2013 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Loss from continuing operations |  | $ | (975,860 | ) |  | $ | (3,215,467 | ) |  | $ | (1,384,019 | ) |  | $ | (4,277,939 | ) |  
| Less: preferred stock dividends |  |  | (479 | ) |  |  | (479 | ) |  |  | (959 | ) |  |  | (958 | ) |  
| Loss from continuing operations
    applicable to common stock |  |  | (976,339 | ) |  |  | (3,215,946 | ) |  |  | (1,384,978 | ) |  |  | (4,278,897 | ) |  
| Income (loss) from discontinued
    operations |  |  |  |  |  |  | 450 |  |  |  |  |  |  |  | 2,413 |  |  
| Net loss applicable to common
    stock |  | $ | (976,339 | ) |  | $ | (3,215,496 | ) |  | $ | (1,384,978 | ) |  | $ | (4,276,484 | ) |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Weighted average common
    shares outstanding - basic and diluted |  |  | 13,144,063 |  |  |  | 8,379,069 |  |  |  | 12,225,987 |  |  |  | 8,166,921 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Earnings per share - basic
    and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Loss from continuing operations |  | $ | (0.07 | ) |  | $ | (0.38 | ) |  | $ | (0.11 | ) |  | $ | (0.52 | ) |  
| Discontinued operations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Net loss |  | $ | (0.07 | ) |  | $ | (0.38 | ) |  | $ | (0.11 | ) |  | $ | (0.52 | ) |  | 
| Potentially dilutive securities | 
|  |  | Three Months Ended
    March 31, |  |  | Six Months Ended March
    31, |  |  
|  |  | 2014 |  |  | 2013 |  |  | 2014 |  |  | 2013 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Options to purchase
    shares of common stock |  |  | 675,000 |  |  |  |  |  |  |  | 675,000 |  |  |  |  |  |  
| Warrants to purchase shares
    of common stock |  |  | 2,866,506 |  |  |  | 2,167,602 |  |  |  | 2,866,506 |  |  |  | 698,904 |  |  
| Series E convertible preferred
    stock |  |  | 127,840 |  |  |  | 127,840 |  |  |  | 127,840 |  |  |  | 127,840 |  |  
| Shares of non-vested
    restricted stock |  |  | 21,000 |  |  |  | 789 |  |  |  | 21,000 |  |  |  | 789 |  |  
| Total
    potentially dilutive shares |  |  | 3,690,346 |  |  |  | 2,296,231 |  |  |  | 3,690,346 |  |  |  | 827,533 |  |  |