Advanced Techniques for the Analysis of Proteins and RNAs

Proteins and RNAs, as fundamental components of cellular machinery, play pivotal roles in the intricate landscape of life [1,2]. They have a spectrum of functions, ranging from acting as crucial structural elements to orchestrating complex signaling pathways and cellular processes [3,4,5,6,7,8,9,10]. Throughout the dynamic stages of development and in biological responses to environmental factors, proteins and RNAs contribute significantly to the regulation of growth, differentiation, the immune response, and other essential biological processes [5,11,12,13,14,15,16,17,18,19,20,21,22]. Recognizing their multifaceted roles and enabling the rapid and accurate detection of proteins and RNAs, including mRNA and microRNA, are imperative to advancing our understanding of cellular dynamics and their implications in health and disease [11,23,24,25,26,27,28].

The advent of novel analytical techniques in recent years has led to an era of remarkable progress in this field. Technologies such as mass spectrometry [29,30,31,32], immunoassays [33,34,35,36], spectral analysis [37,38], chemosensors [39,40,41], and biosensors [41,42,43,44,45,46,47] have emerged as powerful tools that provide unprecedented insights into the functions and interactions of proteins and RNAs [48,49]. These and many other emerging technological advancements [50,51,52] have not only enhanced our ability to unravel the intricacies of cellular mechanisms, but also hold immense potential to reshape the landscape of healthcare and environmental science. The application of these cutting-edge techniques enables us to take a transformative approach to the diagnosis, monitoring, and treatment of a myriad of diseases, ultimately promising to elevate the quality of life of millions worldwide.

With the advancement of technologies, progress has recently been made in the analysis of proteins and RNAs. In this Special Issue of Chemosensors on “Advanced Techniques for the Analysis of Proteins and RNAs”, I am pleased to present a comprehensive overview of the impactful research showcased in nine published papers. These studies represent cutting-edge methodologies and applications in the fields of biosensing, enzymatic assays, liquid chromatography, and colorimetric and fluorescent assays, providing valuable insights into the detailed analysis of proteins, RNA, and associated pollutants.

Two papers within this collection focus on the development of biosensors tailored for the detection of protein levels within living cells. The work by Wu et al. introduces a novel HiBiT biosensor meticulously designed to monitor the stability of YAP/TAZ proteins in cells [53]. Using this biosensor, the authors identified novel small molecules that regulate YAP/TAZ, offering a promising avenue to improving anti-triple-negative breast cancer (TNBC) therapy. This pioneering approach marks a significant stride in cancer drug discovery through the innovative application of biosensing technologies. In a parallel study, Sitkov et al. engineered an impedimetric biosensor featuring zinc oxide nanorods for the highly sensitive detection of biomarkers [54]. Their work underscores the biosensor’s potential for utilization in point-of-care systems designed for the swift, multimodal detection of molecular markers across diverse diseases.

Several other papers employed peptides or enzymes with a high affinity for proteins to quantify proteins or protein-like reagents in vitro. Zimina et al. dedicated their research to designing a peptide ligand with a heightened affinity for proteins such as lactoferrin, a multifunctional protein derived from milk, employing in silico modeling and capillary electrophoresis techniques to study its binding specificity [55]. Shahzadi et al. explored the feasibility of leveraging ultra-thin 2D materials, renowned for their high affinity for proteins and DNA, for biosensing applications [56]. Their evaluation of the non-covalent functionalization of CVD-graphene using a pyrene-based supporter construct demonstrated its potential in biosensing applications, particularly in the detection of proteins like streptavidin. In their contribution, Esimbekova et al. introduced a trypsin-based chemoenzymatic assay tailored for the detection of pollutants and the safety assessment of food additives [57], showcasing the versatility of enzyme-based detection systems for the analysis of reagents akin to enzymatic proteins.

Additionally, Kuznetsov et al. presented a novel chromatographic sensor designed for fast protein and metabolite liquid chromatography, facilitating the evaluation of fish and meat freshness through the analysis of specific protein and DNA contents [58]. The proposed freshness index (H*) demonstrated a strong correlation with traditional freshness indicators. Moreover, Mamaeva et al. and Li et al. conducted insightful comparisons of various colorimetric and fluorometric chemosensors or assays for protein concentration determination, offering valuable insights into the comparative performance of different dyes and assays [59,60].

Finally, Lin et al. contributed a review article on microRNA biosensors tailored for the early detection of hepatocellular carcinoma, summarizing recent advances in biosensor technologies geared towards detecting these pivotal biomarkers [61].

The diverse range of contributions to this Special Issue collectively advance the field of analytical techniques for protein and RNA analysis, providing novel insights, methodologies, and applications that are poised to catalyze further research in these pivotal areas. I extend my sincere appreciation to all the abovementioned authors for their invaluable contributions to this Special Issue.