Frontline Focus: Searching For Smarter Testing

Viviane E. Kim and Hugo Onghai STEM Oct 24, 2021

Testing, testing, testing, was the mantra of Spring 2020. Before the vaccine was available and protocol established, testing was the surest way to track and curb widespread infection. However, long lines and anxious wait periods became synonymous with Covid-19 testing, opening a niche for scientists who wanted to improve the experience.

Senior Hugo Onghai was determined to try his hand at research in the summer of 2020, while the virus was exploding across the United States. The nearby Garcia Scholars Summer Program, a Stony Brook University initiative, caught his eye and he applied. By December, he and his group were presenting their findings at a Material Research Society Symposium virtually in Boston, and their work was on track for a patent.

That’s just an awesome moment—to finally understand.

Hugo and a team of other high school students and graduate students, led by Stony Brook Professor Miriam Rfailovich, developed an electropotential biosensor chip that offers a better method of testing for COVID-19 than current technologies on the market. Essentially, the chip has virus-shaped cavities that can reabsorb viruses present in a sample, subsequently showing an electrochemical response (OCP). Simply, if a biosensor shows an OCP response in a saliva sample, then the sample tests positive for the virus.

The most popular testing method, Quantitative Reverse Transcription PCR (RT-qPCR,) is chronically in shortage and requires uncomfortable swabbing of the nose and throat. From there, the tests are sent off location to be analyzed by expensive equipment, a process that can take days. Since data analysis (obtaining testing results), is inherent in Hugo’s biosensor, and it utilizes mass-produced materials, the test is more cost-effective, convenient, and non-intrusive, one that requires only saliva samples to work. It’s less prone to the chronic shortages of swabs and chemicals that standard testing is saddled with and could take as little as thirty minutes to output results. Most importantly, it’s more accurate.

RTqPCR involves uncomfortable swabbing of the nose, and can be very slow - Mufid Majnun on Unsplash

“Of course it’s not always right, as all testing devices aren’t always right. However, based on previous research, the tests can perform more sensitively and specifically than RT-qPCR,” Hugo said. This high sensitivity and specificity reduces the chance of both false negatives and false positives in testing results, allows the chip to discriminate between viruses with only minor differences in structure, shape, and size, and picks up on the bare minimum trace amounts of virus.

You’ve got to persevere, because it definitely pays off.

So how is the test made? The biosensor chip has a series of layers: bare silicon which is layered with gold and then covered with crystallizing thiol molecules. Gilded silicon chips are commonly mass-produced for various technologies, plus their manufacture is very hazardous, so the team purchased ready-made chips from suppliers including BNL, City University, and Cornell.

The next step is vital. Thiols, chemical compounds that crystallize on gold, are layered onto the chip. Simultaneously, virus molecules are introduced, forcing the thiols to conform around each virion, effectively like a mold. Thus, the crystals are based on the contours of the virus. After imprinting, the virions can be washed away, leaving a chip covered with empty, virus-shaped cavities.

Diagram of a biosensor

“At this point, the chip is ready for testing,” Hugo says. “In a sense, the testing process is just seeing if a sample has virus in it by seeing if empty cavities are filled up.”  That “filling up” is called reabsorption, when you reintroduce the virus into the sample, and it reconnects back to that crystalline shape. On a microscopic level, the researchers can determine if the cavities are filled by measuring the OCP levels. If the electrochemical response decreases, the test reads positive.

Lab Life

Researching Covid, during Covid, sounds like a complicated conundrum. But, according to Hugo, “the experience would have been drastically different without COVID-19, but that isn’t to say that this was drastically worse.” Going virtual opened up new networking opportunities, connecting him with students scattered across the U.S., and even overseas! “It was the first time I really connected to people online without meeting them in person first. That was a really new experience for me,” he said.

That’s not to say the program wasn’t without its rough spots. Due to pandemic protocols, high school students were barred from the lab, leaving the brunt of the lab work to graduate students. Besides “priceless lab time”, Hugo also missed the ease that comes with face-to-face interaction. “They already started the research, so I had to read up on all that background material. If we had been able to do it in person, we could go back and forth, drawing diagrams to help each other explain,” he said. Despite all this frustration, words of encouragement — “you’ve got to persevere, because it definitely pays off.”

As opposed to high school classes, where the curriculum is set from day one, research takes you on real-world adventures with blurry destinations. “As my mentor told me, ‘research is like a huge art piece, and you just have to keep adding strokes, and eventually it’ll come together. It takes time,’” Hugo said. For him, nothing compares to the epiphany of that final clarity. “Watching the experiments, and knowing with all this background information, what’s exactly going on. That’s just an awesome moment—to finally understand.”

There’s a human upside to all this too. Research unites countless people with similar interests – in this case, a hope to make a significant dent in the side of slow and inefficient testing. Camaraderie runs high, with Hugo describing his team as “incredibly nice and knowledgeable. The graduate students were great mentors, very patient. I always felt comfortable to ask questions.” Months of work formed strong bonds between the researchers. “The Garcia Center is like a huge family. I still talk to my new friends all the time, so it’s almost like the program never really ended.”

With so many benefits, Hugo urged anyone considering summer research to seize the opportunity. “It amazes me that high school students can get exposure so early on to these real-world environments and these really professional scenarios. If you’re not sure about it, or having second thoughts, I was too. Let me tell you first hand, that it’s totally worth it.”

Viviane E. Kim

Viviane, a sophomore, is Editor-in-Chief of The Current. She's an aspiring pianist, flutist, artist, and activist. She has won several writing competitions and performed with the SBU Orchestra.

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