Walgreen Co. is encouraging high school students in Chicago and St. Louis public schools to be more aware of their sexual health through the Walgreens Expression Challenge—and it’s using two-dimensional bar codes to connect with mobile-savvy teens.

Students have a chance to win up to $3,000 for themselves, their schools and their teachers for submitting art projects, poems, essays, photos or videos addressing healthy sexual decisions. This year marked the first time Walgreens, No. 42 in the Internet Retailer Mobile 300, included Quick Response codes, a type of 2-D bar code, in the campaign.

Placed on promotional signs, the codes link a consumer with a smartphone-based QR code reader app to a mobile web site where he can enter an e-mail address to get more information or links to the Expressions Challenge Facebook page or contest web site. QR codes are black-and-white or colored squares that can contain much more information than conventional one-dimensional bar codes. They link the physical world—wherever the code is placed—to the mobile world—a mobile web site filled with information.

On average, the code was scanned about 70 times a week during the contest, which ended Nov. 6, says John Gremer, Walgreens director of community relations. “The goal of the program is to get students communicating with their peers and parents,” Gremer says.

Using a QR code made sense, Gremer adds, because a growing number of young people have smartphones capable of scanning the codes. Nielsen last week said that 40% of 12-17 year-old teens own a smartphone. “We’re trying to make it as easy as possible to get information between two parties,” he says. “With students, especially with this topic, you have to speak the language and use the tools and formats they’re comfortable with.” The Expressions Challenge QR codes appeared on posters and on the contest’s Facebook page.

“When you’re dealing with something as serious as HIV and STDs, you have to take a look at every single way to get the message out,” Gremer says.