Quick, extremely correct drug detection important to decreasing the destructive results of habit

Rapid, accessible, and highly accurate detection of addictive substances such as opiates and cocaine is critical to reducing the adverse personal and societal impact of addiction, which can take too long with current drug detection systems. However, real-time monitoring of abused drugs in a patient’s on-site system could alert doctors before dangerous levels are reached, and such an approach may not be far off.

Drug detection methods for addiction patients are slow and not agile enough because of the complexity of the current system, said Slava V. Rotkin, frontier professor of engineering and mechanics, with an appointment at Penn State’s Materials Research Institute. Rotkin is co-author of a review article in the nanotechnology journal Small that posits one possible solution: biosensors.

The first goal of our review is to raise awareness of the problem for hundreds of references available to anyone working in addiction prevention. The second goal is that reviews are usually read more often than the original work. We hope to reach a larger audience of both researchers and the general public through media attention. And we present biosensors as a possible solution.”

Slava V. Rotkin, Frontier Professor of Engineering and Mechanics, Penn State Materials Research Institute

Statistics demonstrate the medical importance of improved and faster drug detection in the human body. According to the CDC, drug overdose deaths increased 137% between 2000 and 2014, including a 200 percent increase in overdose deaths from opioids such as opioid painkillers and heroin.

One of the most important tools to combat this addiction epidemic is drug detection in users, the researchers said. The classic laboratory-based method of monitoring the presence of drugs in patients’ blood or urine, ranging from simple chemical color tests such as thin-layer chromatography to more complex methods such as gas chromatography-mass spectrometry, is reliable and accurate. However, they require samples to be sent elsewhere, which is a time-consuming and expensive process. A quick, cheaper, and more consistent method of monitoring potential drug use could alert physicians to overdoses in their patients.

“If the analysis is very expensive, you will limit the frequency of analysis,” Rotkin said. “It has to be cheap, effective and simple. As simple as possible, because you have to take the blood sample from the patient, and then you have to clean the blood, prepare the samples and take a specialist in a remote laboratory for an hour. This can cost a lot of money and that’s why you wouldn’t go for a regular analysis unless it’s very, very necessary. But with an addiction, you should do it more often just because the problem is so acute.

In the review, the international research team, including Rotkin, listed 203 references to a large body of research that suggests biosensors have great potential to address these challenges. Biosensors could potentially solve this problem by continuously enabling highly sensitive and inexpensive analysis of a patient. A biosensing device includes a small sensor that is exposed to a biological material and produces a chemical, optical, or electrical signal in response to a biostimulus. The design of these biosensors has evolved significantly over the past two decades, appearing on the market in the form of over-the-counter glucose sensors for diabetics and home pregnancy tests. However, for the type of sensors needed for drug detection, Rotkin and his co-authors note that there is a problem: size.

“Based on what we currently have in terms of biosensors, we’re like how it was with cell phones in the early 1990s,” Rotkin said. “We used these huge cell phones, which were about the size of a regular landline phone back then, and you needed a pocket to carry it.”

The use of nanomaterials shows promise and could potentially enable a biosensor to detect opiates and cocaine that would be small enough to fit into a bandage. The nanomaterials would provide a platform for bioreceptors and provide a “nanoarchitecture” on which to build highly sensitive, fast and small detection devices.

The review paper proposed aptamer-based sensors for drug detection. Aptamers are short sequences of either RNA, DNA, or peptides. Aptamer molecules can be specifically designed as recognition elements for biosensors. Properties such as a very small size, a fast and inexpensive manufacturing process, biocompatibility and high stability make them ideal for such a biosensor.

“In the paper, we described all the existing technologies and weighed the pros and cons,” Rotkin said. “This includes the large number of sensors currently based on electrochemical detection, which are extremely simple and cheap. But because of their robustness, ie they can see everything, the question arises as to whether you can be selective and focus on what you want to detect. This is where the selectively constructed aptamers should help.”

Other technologies studied included optical sensing, which relies on the change in optical properties by a stimulus that produces a signal proportional to a substance’s concentration, or its optical ‘fingerprints’. Rotkin is working with the University of North Carolina-Greensboro researchers on such devices that use heterostructures of 2D materials.

Other sensors they checked were microfluidic sensors, which only require a tiny volume of sample for analysis; piezoelectric sensors that respond to applied mechanical stresses; and electromechanical sensors, which are attractive to researchers because they are flexible and can detect micro-sized compounds and particles.

The authors of the review article concluded that the main hurdles to overcome to create such small, wearable biosensors for addicts are the need to improve the reproducibility of the biosensors, especially when analyzing complex sample media, and the ability to fabricate a sensor that does not require any pretreatment of samples in order to analyze them. Furthermore, the authors concluded that more funding is needed to develop marketable biosensors with low price and the right analysis parameters.

“They need adequate funding for this viable biosensor to emerge,” Rotkin said. “And that’s always a challenge. So I and my colleagues are hoping that when people see this review it might allow them to see what people have done in a paper. Maybe they can follow up on one of the researched sensor types and continue until we get the real product.”

The paper’s authors posited that biosensors for in-person and on-site drug abuse monitoring could come to market in the next decade.

“Not everyone can do this in their own lab, so it would take a while to make a finished product,” Rotkin said. “And then you need FDA approval, which takes another year or so, and then you have to manufacture it. I would estimate that the whole cycle can take up to 10 years. Maybe it can be developed and commercialized via a spin-off company created at the university, and coincidentally we have an incubator right here -; Invent Penn State.”

Source:

Penn State Materials Research Institute