The frequent occurrences of viral outbreaks and the ongoing transmission of zoonotic viruses highlight the threat posed by emerging and re-emerging viruses. Pandemics, characterized by widespread and global infection waves with high mortality rates, present a significant challenge for the human health. The emergence of SARS-CoV-2 in late 2019 necessitated the rapid characterization of the virus and the development of targeted countermeasures. Swiftly approved vaccines helped to reduce hospitalization rates and severe disease progression, but new SARS-CoV-2 variants have emerged that can evade immunity, leading to contagion and new infection waves. Recently approved drug regimens protect against severe COVID-19 progression, but only when administered early. These events and the risk from other zoonotic spillovers emphasize the need for broad-spectrum antivirals that can be readily used when encountering a novel virus as a measure of pandemic preparedness. In this study, high-throughput methodologies like flow cytometry and in-cell ELISA were established to quantify hCoV infection, enabling antiviral testing and identification of new inhibitors, including broad-spectrum antivirals. The study's second part focused on enhancing the antiviral activity of a group of broad-spectrum antivirals called molecular tweezers. Molecular tweezers are known to inhibit various respiratory viruses and offer potential for repurposing against newly emerged viruses. The incorporation of a lipid head group into the tweezer's cavity causes an orientation change of the lipid, allowing the tweezer to penetrate the viral membrane's outer layer. This increases tension and subsequently disrupts the viral membrane, enabling tweezers to inhibit enveloped viruses. By chemically introducing aliphatic or aromatic side chains that mimic lipid components and function as lipid anchors, the antiviral activity of advanced tweezers was improved. A structure-activity relationship study identified C6/C7 alkyl and aromatic tweezers as promising lead candidates for further preclinical development. This was confirmed against authentic SARS-CoV-2 in immunodetection assays and TEM analysis. In vivo studies in mice showed complete viral abrogation of SARS-CoV-2 infection by advanced tweezers when mixed with the virus and directly administered, but not in a prophylactic setting, indicating a need for further pharmacokinetic analysis in the upper respiratory tract. Mechanistic studies of the advanced tweezers showed increased membranolytic activity against virus-like liposomes. Unlike ancestral tweezers, advanced tweezers were not limited to binding exclusively to lipids with a choline head group (phosphatidylcholine and sphingomyelin) and exhibited therefore a broader lytic activity. Additionally, advanced tweezers not only incorporated lipid head groups into their cavity but also inserted their introduced side arms into membranes, further elevating viral membrane tension, as demonstrated by computational modeling. Principal component analysis during the characterization of advanced tweezers suggested that the viral budding site and thus the lipid composition of the viral envelope influence the antiviral activity of tweezers. Viral membranes are proposed to contain different lipid head groups that serve as tweezer target, and each lipid species can alter the membrane characteristics in charge, shape, packing density, and fluidity, which may also affect the efficacy of tweezers. To simplify the biological membrane for tweezer investigations, uniform or two-lipid liposomes representing the most abundant lipid types in the membrane were generated and exposed to advanced tweezers. The study revealed a lipid specificity of tweezers, influenced by lipid characteristics and overlapped with the antiviral activity of tweezers against viruses from distinct budding sites and their assumed lipid composition. Additionally, investigations with differently sized vesicles showed that particle size and curvature also impacted the tweezer activity. Tweezers disrupted highly curved liposomes, mimicking viruses with higher efficiency than giant unilamellar vesicles, which represent small cells in size. The C6/C7 alkyl and alkyne tweezers were most effective on small, highly curved particles, increasing their specificity towards viruses. In summary, molecular tweezers as broad-spectrum antivirals presented here are promising candidates for treating known or emerging enveloped viruses. The molecular tweezers were enhanced and characterized to specify their activity against viruses from distinct budding sites.