Capillary-Assisted Molecular Pendulum Bioanalysis.

The development of robust biosensing strategies that can be easily implemented in everyday life remains a challenge for the future of modern biosensor research. While several reagentless approaches have attempted to address this challenge, they often achieve user-friendliness through sacrificing sensitivity or universality. While acceptable for certain applications, these trade-offs hinder the widespread adoption of reagentless biosensing technologies. Here, we report a novel approach to reagentless biosensing that achieves high sensitivity, rapid detection, and universality using the SARS-CoV-2 virus as a model target. Universality is achieved by using nanoscale molecular pendulums, which enables reagentless electrochemical biosensing through a variable antibody recognition element. Enhanced sensitivity and rapid detection are accomplished by incorporating the coffee-ring phenomenon into the sensing scheme, allowing for target preconcentration on a ring-shaped electrode. Using this approach, we obtained limits of detection of 1 fg/mL and 20 copies/mL for the SARS-CoV-2 nucleoproteins and viral particles, respectively. In addition, clinical sample analysis showed excellent agreement with Ct values from PCR-positive SARS-CoV-2 patients.

Health-related quality of life, functional decline, and long-term mortality in older patients following hospitalisation due to COVID-19.

BACKGROUND: Older people are particularly vulnerable to severe COVID-19. Little is known about long-term consequences of COVID-19 on health-related quality of life (HR-QoL) and functional status in older people, and the impact of age in this context. We aimed to study age-related change in health-related quality of life, functional decline and mortality among older patients 6 months following hospitalisation due to COVID-19. METHODS: This was a cohort study including patients aged 60 years and older admitted to four general hospitals in South-Eastern Norway due to COVID-19, from March 1 up until July 1, 2020. Patients who were still alive were invited to attend a six-month follow-up. Change in HR-QoL and functional status compared to before the COVID-19 hospitalisation were assessed using the EuroQol 5-dimensional-5 levels questionnaire (EQ. 5D-5L). A change in visual analogue scale (VAS) score of 7 or more was considered clinically relevant. RESULTS: Out of 216 patients aged 60 years and older that were admitted to hospital due to COVID-19 during the study period, 171 were still alive 180 days after hospital admission, and 106 patients (62%) attended the six-month follow-up. Mean age was 74.3 years, 27 patients (26%) had experienced severe COVID-19. Fifty-seven participants (54%) reported a decrease in the EQ. 5D-5L VAS score after 6 months, with no significant difference between persons aged 75 years and older compared to younger. Seventy participants (66%) reported a negative change in any of the dimensions of the EQ. 5D-5L, with impaired ability to perform activities of daily life (35%), reduced mobility (33%) and having more pain or discomfort (33%) being the most commonly reported changes. Forty-six participants (43%) reported a negative change in cognitive function compared to before the COVID-19 hospitalisation. Six-month mortality was 21%, and increased with increasing age. CONCLUSIONS: More than half of the patients reported a negative change in HR-QoL 6 months following hospitalisation due to COVID-19, and one out of three experienced a persistently impaired mobility and ability to carry out activities of daily living. The results suggest awareness of long-term functional decline in older COVID-19 patients.

Detection of SARS-CoV-2 Viral Particles Using Direct, Reagent-Free Electrochemical Sensing.

The development of new methods for direct viral detection using streamlined and ideally reagent-free assays is a timely and important, but challenging, problem. The challenge of combatting the COVID-19 pandemic has been exacerbated by the lack of rapid and effective methods to identify viral pathogens like SARS-CoV-2 on-demand. Existing gold standard nucleic acid-based approaches require enzymatic amplification to achieve clinically relevant levels of sensitivity and are not typically used outside of a laboratory setting. Here, we report reagent-free viral sensing that directly reads out the presence of viral particles in 5 minutes using only a sensor-modified electrode chip. The approach relies on a class of electrode-tethered sensors bearing an analyte-binding antibody displayed on a negatively charged DNA linker that also features a tethered redox probe. When a positive potential is applied, the sensor is transported to the electrode surface. Using chronoamperometry, the presence of viral particles and proteins can be detected as these species increase the hydrodynamic drag on the sensor. This report is the first virus-detecting assay that uses the kinetic response of a probe/virus complex to analyze the complexation state of the antibody. We demonstrate the performance of this sensing approach as a means to detect, within 5 min, the presence of the SARS-CoV-2 virus and its associated spike protein in test samples and in unprocessed patient saliva.

Health-Related Quality of Life, Functional Decline, and Long-Term Mortality in Older Patients Following Hospitalisation Due to COVID-19 (preprint)

Background: Older people are particularly vulnerable to severe COVID-19. Little is known about long-term consequences of COVID-19 on health-related quality of life and functional status in older people, and the impact of age in this context. We aimed to study age-related change in health-related quality of life (HR-QoL), functional decline and mortality among older patients six months following hospitalisation due to COVID-19. Methods This was a cohort study including patients aged 60 years and older admitted to four general hospitals in South-Eastern Norway due to COVID-19, from March 1 up until July 1, 2020. Patients who were still alive were invited to attend a six-month follow-up. Change in HR-QoL and functional status compared to before the COVID-19 hospitalisation were assessed using the EuroQol 5-dimensional-5 levels questionnaire (EQ 5D-5L). A change in visual analogue scale (VAS) score of 7 or more was considered clinically relevant. Results Out of 216 patients aged 60 years and older that were admitted to hospital due to COVID-19 during the study period, 171 were still alive 180 days after hospital admission, and 106 patients (62%) attended the six-month follow-up. Mean age was 74.3 years, 27 patients (26%) had experienced severe COVID-19. 57 participants (54%) reported a decrease in the EQ5D-5L VAS score after six months, with no significant difference between persons aged 75 years and older compared to younger. 70 participants (66%) reported a negative change in any of the dimensions of the EQ-5D-5L, with impaired ability to perform activities of daily life (35%), reduced mobility (33%) and having more pain or discomfort (33%) being the most commonly reported changes. 46 participants (43%) reported a negative change in cognitive function compared to before the COVID-19 hospitalisation. Six-month mortality was 21%, and increased with increasing age. Conclusions More than half of the patients reported a negative change in HR-QoL six months following hospitalisation due to COVID-19, and one out of three experienced a persistently impaired mobility and ability to carry out activities of daily living. The results suggest awareness of long-term functional decline in older COVID-19 patients.