You need to us ACS Style for your citations. Even though you are retrieving the article from a website, you still need to include the author, date, article title, journal, volume/issue, and page numbers of the article. When applicable you should also include the DOI and/or website.
This tutorial (http://researchguides.baylor.edu/readacitation) will help you understand the purpose of citations and the information that is needed in a citation.