| Cover | Feb. 10, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 10, 2022 |
| Entity File Number | 001-36745 |
| Entity Registrant Name | Applied DNA Sciences, Inc. |
| Entity Central Index Key | 0000744452 |
| Entity Tax Identification Number | 59-2262718 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 50 Health Sciences Drive |
| Entity Address, City or Town | Stony Brook |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 11790 |
| City Area Code | 631 |
| Local Phone Number | 240-8800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value |
| Trading Symbol | APDN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
